I acquired a rust-free 66 Olds tailgate (should be similar to 64-67 A body wagons) complete with glass. The glass is inside (down) and I am trying to disassemble the tailgate. When I apply power to the motor, I here it hum, but no movement. The window regulator mechanism is behind the glass so I can't access anything. Short of breaking the glass, is there any way of removing the glass? I've removed every external bolt I can find. It doesn't appear to be firmly attached to the regulator at the bottom of the glass. Can I turn it upside down and let the glass slide out with a little persuasion?