Need Help with N3ds 9.9 US downgrading and installing cfw.

Hey all, My friend is new to the 3ds scene, and I have always used a gateway since the 9.2 exploit last year, so I have no idea about this new stuff haha.

So anyway my friend is running a 9.9 US n3ds console, are there any guides out there that can allow him to access the homebrew channel and have him downgrade to 9.2 and install cfw?

Any help is appreciated!

Thanks in advance!