I've installed PC-BSD 9.2 and followed your instructions.
It removed the Nvidia 319.xx driver and a lot of other stuff!
Right now,it just keeps saying "updating packages" and has been for quite some time now.
It's 1:20 PM EDT,so I'll wait awhile longer.
Twice I installed the OS and followed the instructions and twice it installed nvidia 304.xx,then proceeded to delete 490 important packages,leaving me with only a text-based system.
I give up -for now! LOL