Door window removal & replacement?

I want to replace my driver's side door window as it is badly scratched. I was at the JY yesterday and saw plenty of XJ's with good glass, but they all had power windows and were left with the window rolled up (no batteries in the vehicles of course), and as far as I can tell you need to be able to lower the window in order to remove it.

I'm guessing I'd need just to lower the window all the way down, unbolt the vent window frame and remove it, roll the window up partway and unbolt it from the regulator, and then I assume it'd lift right out.... Correct? But how can I do this on an XJ with power windows when the power windows aren't operational? I tried to figure out how to disconnect the window motors from the regulator, but I couldn't tell where or how they attach, and the motors are riveted in place, so...? Any advice?

You can use a battery from a cordless drill/driver provided it's at least 12 volt.

Use jumper wires, ground to door then + to either side of motor connector to go up/down.