Users have reported this not working when your nands are still linked! I recommend unlinking your nands first! Read the section "
Emunand Information" below!
Download
FBI.cia
1. Boot up your 3DS and launch rxTools. Hold L when the bottom screen glitches to get into the menu.
2. Press dpad RIGHT to go to Advanced Options -> Press A -> Install FBI -> Press A -> choose EMUNAND, then select "check TMD version".
If you want to install GBA/DSi games in the future:
Choose sysnand the second time you go over this section (Step 4a)
3. Take note of the console region and the TMD version, and turn off your 3DS.
4. Open the rxtools download and open the "Tools/fbi_injection/[region]/[version]" folder and copy the "fbi_inject.app" and "fbi_inject.tmd" files to the SD card root dir.
5. Put the FBI.cia from the FBI download onto your sd card
6. Boot up your 3DS and launch rxTools. Hold L when the bottom screen glitches to get into the menu.
7. Press dpad RIGHT to go to Advanced Options -> Press A -> Install FBI -> Press A -> choose EMUNAND, then select "Install FBI". When it's done, it will ask what you want to do with the source. Select "keep" if you want to install FBI to sysnand later.