Sedan Door Glass Installation Question

I'm trying to install the door glass into the door and wonder if anyone knows the correct procedure ('68 Valiant). Right now I have dropped the glass and regulator into the door but not bolted it in. I then thread the vent window assembly in. However, if I fully install the vent window I can't get the main glass into the channels. If I try to slide the vent window over the corner of the main glass into position it won't go. Anybody done this? I wish I had a manual. :smile: