Hi,
this forum is pretty death lol
download this hybrid firmware http://tinyurl.com/opuby7z unzip every thing to a SD card use a PC not a mac.
now go here http://avic411.com/index.php?/topic/22876-fresh-30-install-on-f90bt-with-pictures/
do Step 1 to step 14, you dont need 3 sd cards
i have done everything with one 8gb sd card, i just copied everything to the sd card