Since Decrypt9WIP (Aug 2016 or later) 's CTRNAND transfer enhanced the region changing, we don't need the old tutorial's Part 1 ~ Part 11 now.

From Plailect's Guide (CTRNAND transfer based):

Preparations
- TWN/CHN 3DS 4.1-9.2
- DS Flashcart (for 4.1-4.5, optional)
- Decrypt9WIP
- 2.1.0-4 JPN/USA/EUR CTRTransfer image
- SafeA9LHInstaller
- AuroraWright's A9LH fork
- data_input_v2
- Luma3DS

New Part 1 - Boot Decrypt9WIP

For 4.1-9.2 with browser:

N1-1-1) Put Launcher.dat from Decypt9WIP to SD root
N1-1-2) Use Internet Browser to visit http://go.gateway-3ds.com/ (or http://soar.im/go/) to boot Decrypt9WIP

For 4.1-4.5:

N1-2-1) Put Decrypt9WIP.dat to SD root
N1-2-2) Use DS Flashcart to install Decrypt9WIP.NDS
N1-2-3) Boot Decrypt9WIP by MSET

New Part 2 - Use Auto CTRNAND transfer to do all the following things
- Backup TWN/CHN SysNAND
- Change region to your selected one: JPN/USA/EUR
- Downgrade SysNAND to 2.1.0-4J/U/E

See Plailect's Guide.

New Part 3 - Install A9LH

See Plailect's Guide.

New Part 4 - Restore TWN/CHN SysNAND (or TWN/CHN EmuNAND) to A9LH SysNAND

N4-1) Rename Decrypt9WIP.bin into X_Decrypt9WIP.bin
N4-2) Put X_Decrypt9WIP.bin into SD:/luma/payloads/
N4-3) Put TWN/CHN EmuNAND backup to SD:/files9/
N4-4) Hold X on power-on to boot Decrypt9WIP
N4-5) Go to SysNAND Options -> SysNAND Backup/Restore... -> NAND Restore (keep a9lh) to inject TWN/CHN EmuNAND to A9LH SysNAND
N4-6) All done!

* If you want to change H&S into any software on TWN/CHN A9LH SysNAND, delete 0004001000026300 (TWN) 0004001000028300 (CHN). Otherwise Decrypt9WIP cannot dump hs.app properly!

--------------------------------------------------
[Previous Tutorial]

This tutorial is an English translation + optimization from original Chinese tutorials written by blueGG / Soarqin / 中2612222 in bbs.duowan.com .

I don't know whether it works on KOR or not.
If you have all the backups & soldering skills, you can follow the theory to try it yourself.

Abstract:

Part 1 ~ Part 7 --- Change TWN/CHN SysNAND into JPN/EUR SysNAND
Part 8 ~ Part 12 --- Install A9LH
Part 13 --- Restore TWN/CHN EmuNAND into A9LH SysNAND

Preparations:

- TWN/CHN 3DS 4.1-9.2
- DS Flashcart
- JPN/EUR O3DS/O3DSLL Secureinfo_A
(O3DS Secureinfo_A for TWN O3DS.
O3DSLL Secureinfo_A for TWN/CHN O3DSXL.
Do not use 2DS/N3DS/Source_Unknown Secureinfo_A or your TWN/CHN CONSOLE will be BRICKED!
Do not use Secureinfo_A from Internet because they're Source Unknown and they have already BRICKED some consoles! Use a real dump instead.)
- Selected titles from JPN/EUR 4.5.0-10 pack
(Do not install ANY TITLE outside the following LIST or it may cause a BRICK!)

4.5.0-10J
0004001000020000 v3074
0004001000020100 v2051
0004001000020200 v2051
0004001000020300 v1024
0004001000020400 v2048
0004001000020500 v3072
0004001000020700 v1026
0004001000020800 v4096
0004001000020900 v6146
0004001000020a00 v2050
0004001000020b00 v1034
0004001000020d00 v1028
0004001000020e00 v1026
0004001000020f00 v1024
0004001000023000 v2048
0004001b00010702 v0
0004003000008202 v6146
0004003000008402 v1036
0004003000008602 v3072
0004003000008702 v2049
0004003000008802 v2050
0004003000008d02 v4099
0004003000008e02 v3075
000400300000c002 v2053
000400300000c003 v0
000400300000c102 v1026
000400300000c302 v1024
000400300000c402 v3
000400300000c502 v3074
000400300000c602 v2050
000400300000cd02 v1026
0004009b00010402 v3072
0004009b00010602 v2
0004009b00011902 v0
0004009b00012202 v4096
0004009b00013202 v0
0004009b00015202 v0
000400db00010302 v4096
000400db00010502 v6144
000400db00016202 v160
000400db00017202 v4176
0004013800000003 v5632
0004013800000102 v6704
0004800f484e4841 v8192

4.5.0-10E
0004001000022000 v3075
0004001000022100 v2051
0004001000022200 v2054
0004001000022300 v2050
0004001000022400 v2048
0004001000022500 v3072
0004001000022700 v1026
0004001000022800 v4096
0004001000022900 v6146
0004001000022a00 v2050
0004001000022b00 v1034
0004001000022d00 v1028
0004001000022e00 v1026
0004001000022f00 v1024
0004001000025000 v2048
0004001b00010702 v0
0004003000009802 v6146
0004003000009902 v1036
0004003000009b02 v3072
0004003000009c02 v2049
0004003000009d02 v2050
0004003000009f02 v4099
000400300000a002 v3075
000400300000c502 v3074
000400300000cd02 v1026
000400300000d002 v2053
000400300000d003 v0
000400300000d102 v1026
000400300000d302 v1024
000400300000d402 v3
000400300000d602 v2050
0004009b00010402 v3072
0004009b00010602 v2
0004009b00011202 v0
0004009b00011302 v0
0004009b00011502 v0
0004009b00011702 v0
0004009b00011802 v0
0004009b00011b02 v0
0004009b00011c02 v0
0004009b00011d02 v0
0004009b00012102 v4096
0004009b00013102 v2049
0004009b00015102 v1024
000400db00010302 v4096
000400db00010502 v6144
000400db00016102 v160
000400db00017102 v4176
0004013800000002 v7712
0004013800000003 v5632
0004013800000102 v6704
0004800f484e4841 v8192

* USA is theoretically available. But we don't have the selected list of 4.5.0-10U so USA is not introduced at the moment.

- EmuNAND9
- Gateway Launcher
- TWN/CHN gateway.dg
- rxTools BlackJack Preview 4
- rxTools FBI Injection TWN/CHN files
- BigBlueMenu
- latest FBI

- 10.7.0-32 JPN/EUR pack
- 2.1.0-4 JPN/EUR pack
- Tinyformat
- PlaiSysUpdater
- OTPHelper
- SafeA9LHInstaller
- AuroraWright's A9LH fork
- data_input_v2
- Luma3DS
- Decrypt9WIP

Part 1 - Backup TWN/CHN SysNAND and EmuNAND

1-1) Use DS Flashcart to install EmuNAND9.NDS
1-2) Boot EmuNAND9 by MSET
1-3) Backup TWN/CHN SysNAND for emergency
1-4) Backup TWN/CHN EmuNAND and SD:/Nintendo 3DS/ for final use when installing A9LH successfully

Part 2 - Downgrade SysNAND to 4.X (For TWN/CHN 4.X, skip this part)

2-1) Put GW Launcher.dat and TWN/CHN gateway.dg to SD root
2-2) Visit go.gateway-3ds.com with your browser
2-3) Follow the Gateway Downgrade Tutorial to do the downgrade

Part 3 - Change SysNAND H&S into FBI 1.3.8

* To be noticed that Decrypt9WIP H&S dumping on TWN/CHN is blocked by TWN title 0004001000026300 / CHN title 0004001000028300. Unless Decrypt9WIP can fix this, we still need to use rxTools-FBI.

3-1) Put TWN/CHN FBI injection file to SD:/rxTools/
3-2) Use DS Flashcart to install rxInstaller.NDS
3-3) Boot rxTools configuration menu by MSET
3-4) Go to Advanced -> Install FBI -> Taiwan 4 / China 4, then wait for the installation to be succeeded

Part 4 - Install BigBlueMenu to SysNAND

4-1) Put BigBlueMenu.CIA to SD
4-2) Boot rxTools Pasta Mode by MSET
4-3) Run H&S (It's now FBI 1.3.8) -> Install BigBlueMenu.CIA, then wait for the installation to be succeeded

Part 5 - Install SELECTED 4.5.0-10 JPN/EUR titles to SysNAND

* Repeat again! Do not install any 4.5.0-10 title NON-SELECTED! Otherwise it can cause a BRICK!

5-1) Put SELECTED 4.5.0-10 JPN/EUR pack's all files to SD:/updates/
5-2) Boot rxTools Pasta Mode by MSET
5-3) Run BigBlueMenu
5-4) Go to SDMC:/updates/, move cursor to any title, then press L+R+A to import all CIA

Part 6 - Inject JPN/EUR Secureinfo_A to SysNAND

* Use JPN Secureinfo_A if you installed SELECTED 4.5.0-10J.
Use EUR Secureinfo_A if you installed SELECTED 4.5.0-10E.
Do not cross region! Otherwise, BRICK, BRICK, BRICK!!!
* Repeat again! Do not use Secureinfo_A from Internet because they're Source Unknown and they have already BRICKED some consoles! Use a real dump instead.

6-1) Put JPN/EUR Secureinfo_A on SD:/rxTools/
6-2) Boot rxTools configuration menu by MSET
6-3) Go to Inject -> SysNAND -> Files -> Secureinfo_A, then wait for the injection to be succeeded

Part 7 - Delete all the leftover NAND titles not exist on 4.5.0-10 JPN/EUR on SysNAND

7-1) Put the latest FBI.CIA on SD
7-2) Boot rxTools Pasta Mode by MSET
7-3) Run BigBlueMenu to install the latest FBI.CIA
7-4) Download CompareTitlesCSV.py to your PC from this page
7-5) Download 4.5.0-10 Titlelist CSV to your PC from this page
7-6) Rename the downloaded CSV into 4.5.0-10.csv
7-7) Put CompareTitlesCSV.py and 4.5.0-10.csv on the same folder
7-8) Run the following command which suits for your console region & selected Secureinfo_A region to get the NAND titles you should delete

python compareTitlesCSV.py 4.5.0-10.csv 4.5.0-10.csv -region1 TWN -region2 JPN
python compareTitlesCSV.py 4.5.0-10.csv 4.5.0-10.csv -region1 CHN -region2 JPN
python compareTitlesCSV.py 4.5.0-10.csv 4.5.0-10.csv -region1 TWN -region2 EUR
python compareTitlesCSV.py 4.5.0-10.csv 4.5.0-10.csv -region1 CHN -region2 EUR

7-9) Run the latest FBI
7-10) Delete the NAND titles from the compared result

Part 8 - Create JPN/EUR EmuNAND

8-1) Use DS Flashcart to install EmuNAND9.NDS
8-2) Boot EmuNAND9 by MSET
8-3) Wipe out current EmuNAND
8-4) Clone SysNAND to EmuNAND

Part 9 - Upgrade JPN/EUR EmuNAND to 10.7

9-1) Put 10.7.0-32J/10.7.0-32U pack to SD:/updates/
9-2) Use DS Flashcart to install rxInstaller.NDS
9-3) Boot rxTools rxMode EmuNAND by MSET
9-4) Run BigBlueMenu
9-5) Go to SDMC:/updates/, move cursor to any title, then press L+R+A to import all CIA

Part 10 - Downgrade JPN/EUR EmuNAND to 2.1

10-1) Put 2.1.0-4 JPN/EUR pack's all files to SD:/updates/
10-2) Boot rxTools rxMode EmuNAND by MSET
10-3) Tinyformat EmuNAND twice
10-4) Install PlaiSysUpdater to EmuNAND
10-5) Run PlaiSysUpdater to downgrade EmuNAND to 2.1.0-4

Part 11 - MSET OTPHelper

11-1) Use DS Flashcart to install OTPHelper.NDS
11-2) Boot OTPHelper by MSET
11-3) Backup JPN/EUR SysNAND and JPN/EUR 2.1.0-4 EmuNAND for emergency
11-4) One Click Setup (This will inject 2.1.0-4 EmuNAND to SysNAND so you must do the 11-3 backup before this!)

Part 12 - Install A9LH

See Plailect's Guide.

Part 13 - Restore TWN/CHN EmuNAND backup to A9LH SysNAND

13-1) Rename Decrypt9WIP.bin into X_Decrypt9WIP.bin
13-2) Put X_Decrypt9WIP.bin into SD:/luma/payloads/
13-3) Put TWN/CHN EmuNAND backup to SD:/files9/
13-4) Hold X on power-on to boot Decrypt9WIP
13-5) Go to SysNAND Options -> SysNAND Backup/Restore... -> NAND Restore (keep a9lh) to inject TWN/CHN EmuNAND to A9LH SysNAND
13-6) All done!

* If you want to change H&S into any software on TWN/CHN A9LH SysNAND, delete 0004001000026300 (TWN) 0004001000028300 (CHN). Otherwise Decrypt9WIP cannot dump hs.app properly!

 

[DavidKang]

Nice. With a little changes a Korean 3DS will be also possible then.

 

[Kayleea]

thanks for sharing with us.

 

[thisisallowed]

I reccomend flashing a 2.1 CTRNAND using decrypt9
It is very fast and easy
But there are no apps on 2.1 homemenu on China Korea and Taiwan reigons, so if you don't have internet you must go to safemode

 

[MelonGx]

I reccomend flashing a 2.1 CTRNAND using decrypt9
It is very fast and easy
But there are no apps on 2.1 homemenu on China Korea and Taiwan reigons, so if you don't have internet you must go to safemode

The NAND has already been changed into JPN/EUR when using OTPhelper so nothing to do with TWN/CHN NAND.

 

[thisisallowed]

The NAND has already been changed into JPN/EUR when using OTPhelper so nothing to do with TWN/CHN NAND.

You don't have to do all of this comlicated prossess to change the nand
You need to get a 2.1 CTRNAND, boot decrypt9 on your 4.0-9.2 Korea China Taiwan console, and do auto ctrnand transfer
No emunand needed, no fbi
It's automatic and easy

 

[MelonGx]

You don't have to do all of this comlicated prossess to change the nand
You need to get a 2.1 CTRNAND, boot decrypt9 on your 4.0-9.2 Korea China Taiwan console, and do auto ctrnand transfer
No emunand needed, no fbi
It's automatic and easy

.....and risky without hardmod.

 

[thisisallowed]

.....and risky without hardmod.

No because you are restoring CTRNAND
I tested using plailect 9.2 image on emunand, works great, from 11.0U to 9.2E
If you make an easy guide then it's simple

 

[cearp]

i was interested to read something new, until i saw it's just region changing lol

but thanks for the guide anyway!