new method to use this:
download the latest waithax .3dsx release on my repo
here,
run it, and then run whatever you want when it's done running: 3ds_dsiwarehax_installer, etc...
you can download most of these apps from their original authors, no modifications/forks needed.
for fbi, you need to use my fork which removes the integrated khax exploit (probably, but just use it to be safe i guess and not have to do it again, i only got crashes on stuff with the releases):
https://github.com/Mrrraou/FBI/releases/download/v2.4.2-nok11hax/FBI.3dsx
also, take note that rebooting will "remove" all the privilege escalation done, so don't reboot until you're done, else you will have to run waithax again.
Enjoy