have you burned the firmware update to a cd if you have it should be easy as all you then do is put the firmware cd in let it autoboot and follow a few on screen prompts and dont turn your machine off it dont take long to update.
I ignored the imformation to burn the cd using linux it was much easier and faster with windows and nero.
what amigaone do you have is it the 600 g3 or a g4 xe. :-?