Back in the 70s I owned a VW repair shop and we would put windshields in the old bugs. This method works with both flat and curved glass.
You will need: A piece of heavy string, I use the kind that is used for making chalk lines; a small screw driver; some dish washing soap; and a second person to make sure nothing drops to he ground.
Start by putting the rubber around the glass. Put some soap around the lip and on on the rubber edge that goes over the lip.
Set the bottom strip over the lip on the door where the two ends of the rubber come together. You should be working from the inside of the door. Have the other person put his hand on the glass just to hold it in place because you may push against the glass accidentally.
Start pulling one or both of the ends of the string, this will pull the rubber over the lip. Continue around the glass with the other person putting a slight bit of pressure on the glass. In case the string does not pull the rubber in, use the small screwdriver to lip the rubber over.
The soap is what makes the job easy. I don't recommend silicone spray as I felt this may harm a new paint job.
I used to put windshields in in less than 10 minutes.
Jack Sim
Author, 1st & 2nd editions of Gas Pump ID book, 3rd edition is now available at
www.gaspumpbible.comAir Meter ID book also available