Part 1 (Changing CFW and ShadowNAND)

You cannot use another console's OTP or you will brick GUARANTEED.

This guide will provide you with two options for using Custom Firmware on SysNAND via arm9loaderhax, Luma3DS, Gateway, DSTWO, ReiNAND, SaltFW and CakesFW.

Luma3DS, ReiNAND and SaltFW is a more feature rich CFW in addition to being more noob friendly, and are recommended for beginners, while CakesFW is a more complex CFW that is recommended only for advanced users. Otherwise, they perform a similar function and you can use either according to personal preferences.

If you need more information on what CFW to run, see here

Gateway and DSTWO, however, are like Decrypt9 and a CFW with it. They require a flashcart and unless you don't have one of these, you should just follow the Luma3DS guide.

Currently, Luma3DS supports Region Free patches, which enable users to install games from any region without any extra modification or steps, and AGB_FIRM/TWL_FIRM patches, which enable users to use installed GBA games and DSi homebrew without manually patching files.

During the process, we'll be installing ShadowNAND (a CFW in your NAND that lets you boot without your SD card), HourGlass9 (a A9LH NAND tool), FBI (A .CIA manager and installer), EmuNAND9 (A full SD card tool), SafeMode9 (A full NAND decryption tool) and Decrypt9WIP (A Full NAND tool).

If you currently have ShadowNAND and want to switch to a different CFW, each link contains instructions for switching to it from the other.

If you currently want to keep Luma3DS, follow the Luma3DS guide.

Categories	List of CFW that will work with it
Beginner	Luma3DS
	SaltFW
Intermediate	ReiNAND (Recommended on New 3DS)
Flashcart	Gateway
	DSTWO Plus (Old 3DS users only)
Advanced	Cakes

Be advised that AuReiNand has officially changed its name to Luma3DS.