Side Window install question...HELP!

Ok, I am trying to re-install the side windows in my 71. I fought the back seat side glass, and won. The front seat side glass is about to kill me. I have the regulator installed, the rails that the glass rides up are in. When I try to put the windows in, I can barley fit the glass into the area. Since I did not take out the glass, I have a couple stupid questions. First, do I need to remove everything from the glass, slide it it, and attach the fasteners that go through the window while its in the door, or am I supposed to be able to fit it in as an assembly? I did not have to dis-assemble the rear side glass, so I do not know if I need to on the front. Second dumb questions, shouild I pull out the rails, insert the glass, and then try to set the side rails? What is the correct order for installing these? Any help is greatly appreciated!!