http://gbatemp.net/threads/nobody-discussing-kor-twn-chn-regions-a9lh.432742/
You need:
- A real JPN/EUR/USA O3DS console whose Secureinfo_A can be dumped.
- Decrypt9WIP, FBI, rxTools Pasta Mode etc.
- O3DSes are only compatible with O3DS Secureinfo_A.
- N3DSes are only compatible with N3DS Secureinfo_A.
- 2DSes are only compatible with 2DS Secureinfo_A.
-
Do not use any Secureinfo_A from either of 2DS, N3DS, Internet Download, otherwise your O3DS KOR will brick!
Steps: (Assuming you have an O3DS EUR for region changing)
1. Dump EUR Secureinfo_A
(Repeat again. Do not use Internet shared Secureinfo_A otherwise it can cause a brick!)
2. Downgrade your O3DS KOR to 9.0
3. Backup 9.0 KOR SYSNAND
4. Install 9.0.0-20E to SYSNAND (in PASTA MODE)
5. Inject EUR Secureinfo_A to SYSNAND
6. DELETE all NAND titles which 9.0.0-20E doesn't have
Now your O3DS KOR becomes O3DS EUR.
7. Do the 2.1.0 Downgrade and make A9LH
8. Restore 9.0 KOR SYSNAND with Keep A9LH