This guide assumes you have access to RCM, if you do not, use a compatible method. Some of those compatible methods can be found here.
This guide will transform your stock switch to play "backups" of switch games
1.) Installing ReiNX

• Download the latest stable ReiNX Release (Found here) (Extract this on to the root of your SD)
• Make a new folder in the /ReiNX/ directory on your SD named 'titles'
• Download hbmenu.nro (place this on the root of your SD)
• Download this .zip file and extract it to /ReiNX/titles/
• Download the latest stable release of Tinfoil(Found here)
• Create a new folder on the SD's root named 'switch'
• Place tinfoil.nro (found in the tinfoil zip) in the /switch/ directory
• Make a new folder on the root of the SD named 'tinfoil' and inside this folder create another folder named 'nsp'

*From now on any NSP warez or homebrew you download should be placed in /tinfoil/nsp on the SD card.

2.) Booting into ReiNX
*Skip this step if you are familiar with booting into CFW

• Use your method of choice to enter RCM
• Push ReiNX.bin from the ReiNX.zip we downloaded earlier to your switch. (If you do not know what app to use to do this i reccomend TegraRCMGUI for Windows users.)

3.) Installing Games

• Open the homebrew launcher by opening the Nintendo Switch Album
• Open tinfoil
• Choose Title Management>Install NSP>(Choose the NSP you would like to install)

Profit! Enjoy your "legally obtained backups"

FAQ:

- Can I delete .NSP files from my SD after they have been installed via tinfoil?
Yes you can.

- Will I get banned for going online?
Yes, you will most likely be banned from playing online with your switch. This in fact does not block updates though, and you can still access the eShop. (I strongly suggest you keep your switch in Airplane mode and de-link your NNID if you plan on using CFW to install a bunch of NSPs.)

- Can I install updates or DLC with this tool?
Not with tinfoil currently, you have to install devmenu to install DLCs and game updates. See here: https://gbatemp.net/threads/quick-g...ates-dlc-with-devmenu-no-sx-os-needed.512337/

- Can I convert .XCI to .NSP?
Yes. Use this.

- Do i have to use the album to launch into the homebrew launcher?
No. You can install this via tinfoil and launch the homebrew launcher as if it is an app if that pleases you.

- I wish i could backup my saves so that i don't lose them...
Download checkpoint.nro and use it to backup your saves/import saves from another switch.

- Can i install any homebrew to my main menu with this?
Pretty much. Check this out.

- How do i update ReiNX?
You can update it manually by downloading the latest release and extracting it to the root of your SD card, or use this updater homebrew application. (Recommended you use that homebrew to decrease hassle every time you want to update.)

 

[Oriordan]

Does the installed game on the internal memory need the payload injection after reboot ?

 

[Ashura66]

Does the installed game on the internal memory need the payload injection after reboot ?

Yes

 

[optimusxcrime]

Is this confirmed working on 4.1? When booting ReiNX I get the message "INI1 encrypted" and then my Switch shuts off. I tried this both before and after applying the exFAT mod (which was succesful) and still got the same error both times.

EDIT: Corrected the console message

it's working on my 4.1.0 flawlessly. what version is your SDFiles? i have SDFilesV904. I inject with hekate_ctcaer_4.2
But I dont run cfw. I launch ReiNX payload from the bootloader. (Hit launch when hekate loads up, then payloads and select ReiNX.)
and every game i have works perfect. The tricky part was getting my keys. since kezplez wold not fetch them.
hope this helps!

--------------------- MERGED ---------------------------

Quick question. is "Hello Neighbor" a Cart2 game. I cannot get it to work for the life of me. And my daughter wants it very bad.

Thanks for your time!
cheers

 

[MarioShadow]

where exactly my games and saves go when i install a nsp file on a sd card? can i get these Games files and port to another SD card without installin the NSPFile?

 

[Draxzelex]

where exactly my games and saves go when i install a nsp file on a sd card? can i get these Games files and port to another SD card without installin the NSPFile?

If you install an .NSP file into the SD card, the game is stored on the SD card but the saves will remain on the console. The game is specifically installed into the Nintendo folder on your SD card so as long as you have that, you can move this folder onto other SD cards to use with your console.

 

[KuroTheBang]

“- Can I convert .XCI to .NSP?
Again, no. Anyone, or anything that tells you this is possible is currently incorrect.”

I would edit that lol

 

[IHOP]

“- Can I convert .XCI to .NSP?
Again, no. Anyone, or anything that tells you this is possible is currently incorrect.”

I would edit that lol

The OP has been updated on current methods of installing ReiNX, and installing games via Tinfoil. The FAQ has been updated to accommodate the recent developments in converting XCI files to NSP files.

--------------------- MERGED ---------------------------

where exactly my games and saves go when i install a nsp file on a sd card? can i get these Games files and port to another SD card without installin the NSPFile?

Check the new FAQ

 

[Deleted member 387400]

hey am having a error code while installing a game tinfoil . i am getting error code failed to install NSP! OpenFileSystemWithId:103: Failed to open file system with ID error code 0x00234a02

Did you ever fix this error? I'm currently getting the same one

 

[IHOP]

Did you ever fix this error? I'm currently getting the same one

Could've sworn this was related to FW Version you're on. What FW you on?