One question at a time mate

Taking the CP off - not too hard. Lift the monitor hood and you'll see two metal clips facing the monitor under the CP. Push them in and you can now move back the top of the CP. It may be tricky to slide it off and may need a screw driver wedged in the gap. Make sure you unplug the wire interfaces for player 1 and 2 before fullying taking it off (you'll know them when you see it).
After that, the rest comes off by removing lots of screws, as seen on my site. Just note what screw goes where!
Taking the whole cab apart takes a good few hours, mainly because you area always finding new screws. Just go slow. I had to take the monitor out myself, be careful here it is very heavy and awkward and you'd benefit from having some help.
The PC amp was easy. It's literally a standard subwoofer / amp which had two speakers you connected with standard phono leads. Buy a couple of phono plugs, cut the cab speakers at the bottom [where they'd plug in to the Q-Sound amp] so you just have wire, and wire them in to the phono plugs. Easy. Can't recall but I think the earth is the outer casing on the phono plugs. I guess you should watch impedence and check the amp matches the ohms of the speakers, but I didn't and they work fine for me.
Good luck, and more questions please post them, and keep us updated of your progress!
Matt
PS - in reply to other posts, I also really like the Q-Sound grills. I had them repainted as they were faded and a little rough in places, I think it really makes the cab stand out
