Looks like no one else is commenting, and I have done this 4-5 times, but never the way the pro's do it. Put rubber in the opening on the flange, but it will probably fall out at the top. Set the glass on it and start to work it into the rubber at the bottom.

Use a wooden paint stick, or plastic to help you move the rubber around the glass, and a strong dish soap solution to lubricate the rubber/glass.

DO NOT FORCE the glass, do not push down on the glass. From the bottom work up the sides and eventually the glass won't be laying on the rubber, but will go in and find its position in the car. But that won't happen until the very last of the rubber is plied around the glass. Again, dish soap lubricant is your friend and will help that last "slip into place"

This takes me 2-3 hours, and as you work up the pillars the glass will be farther out, but eventually go in towards the car and allow you to finish the top. If not, its because the glass is not sliding into the gasket in all places, lube it up and it will.

Good luck, remember do not force, do not push. The rubber will pull it into final position.

The new rubber will make this job much easier for us non-pro's.