You can install menuhax on 9.2 or whatever sysNand you're on, and then use FBI.3dsx through the Homebrew Channel to install the FBI.cia to emuNand.
At least, that's how I remember doing it. It's really early and I'm really tired, so someone correct me if I'm wrong.

Inject FBI into Health & Safety Application. Search a tutorial for that.
(For you guys: if you suspect he may be talking through a translator, refrain from writing abbreviations!)
please read the guidesthank for your reply but i try a new rxPasta cfw so how can i install cia with that cfw