Make sure they didn't put the arm9loaderhax.bin in the ctr nand. You can check this with the latest FBI. If it is, copy to sd card and then delete from ctr nand. Then simply use safea9lh installed to uninstall it. Way faster than making a nand back up.
Launching the homebrew menu through cia, they're unable to open safea9lh installer. They say it's just a black screen.