This is a spiritual follow up to this

I am doing some modern OpenGL tutorials and I have found that MESA does not support openGL 3.0+, so I need to get back to FGLRX even if its given me grief in the past.

Every time I have tried to install FGLRX drivers I generally get thrown to the terminal and have to do some recovery, etc. before I can get them to work.

Problem is, now that my main monitor is borked, when I install FGLRX drivers I cannot boot to terminal.

Question: How do I back up my current windowing so that when I (inevitably) lost my boot due to FGLRX installation, I can recover it with a livecd without reinstalling, and how can I install it without a main monitor?