Rear movable window replacement '88 Jetta

[bcatt]

My rear window was smashed in my 1988 Jetta. I have removed the panel, the winding mechanism, and the steel beam inside the door that minimizes crush in collisions (what's the proper name for that anyway?), but I still can't get the window to slide through the opening near the bottom of the door. Is there a trick to it, or do I have to remove the non-movable window panel and put the movable panel in from the top? Will go take pictures now to show the opening in the door that I've been trying to slide the window through.