I could use some words of advice on the installation of the door glass assy back into the door. From what I can find in manuals, etc., the vent assembly should be in place first. I originally tried to install the glass assy with the door rear window run in place,but that seemed impossible. I decided to install the glass assy without the rear run (track) in place and that, though difficult worked. But, now I can't seem to get the rear run in place with the window rolled all the way up. Is there an easy way to do this? At $350 each, I don't want to risk breaking the glass, which is still original at this point.