1990 Chevy Truck

Drivers power window malfunctioning. Window goes down about 1/4" and stops. It sounds like it is jamming. I took the door panel off. There is a sheet metal panel attached by screws to the inside of the door frame. The motor and regulator are attached. I have not been able to remove the sheet metal panel. The motor and regulator are attached the this panel. Also control rods for the locks are attached to this panel. Do I drill out the rivets and remove this panel to access the window track, etc. To inspect and repair the window channel and inner workings? Also what is a good manual with pictures/drawings of the inside components of this power window system.

Thank you.