Buick Riviera

I have a 92 Riviera, 90K miles 3.8L.
The dirivers window will stop working partway through the cycle ( up or down).
Letting it cool will let it go a bit more. Helping by pulling/pushing on the window helps. If you toggle the switch back and forth so that the gear only turns without the regulator moving, or any pressure on the motor ( just the gear slop) it stops.
I believe the motor is bad, and bought a replacement motor, and it comes with a small bracket/plate.
The Haynes manual has NOTHING about window replacement, and it looks like if I grind the rivets off and remove it (or parts of it) I may not be able to get it back together, and I am pretty competent.
Can someone enlighten me on the right procedure?
July 20, 2007.

Check out the related content below while we wait for the question to be answered by a professional mechanic.