I put the gasket on the windshield first, then run a small diameter, well lubed, nylon rope in the inner groove with the ends overlapping at the bottom. Set the lower part of the windshield/gasket assy into place as best you can. Start pulling the rope ends out of the groove from the inside of the car starting at the middle and working your way evenly out to the corners. Do this slowly, making sure the gasket stays seated deeply over the lip. Take special care in the corners and don't force it. Work evenly from side to side so you don't put the glass in a bind. Then, when you find out your gasket is too hard and stiff and you break the glass, you'll have some experience in installing the next one!