Any Professionals have tips for installing windshields?

Install gasket on window. Put a 1/4" rope in the outside gasket channel all the way around so both ends of the rope end up at the bottom in the center. Use a length of rope about twice as long as it takes to go around the channel so you will have plenty to pull on.

Soak the rope down in the channel with Dawn dish washing detergent. Now position the window and gasket into the channel on the bottom side first. You should just about be able to get the bottom side completely in the channel all the way across.

With a friend on the outside, applying firm pressure at the bottom where the rope ends come out, start pulling one end of the rope out at a 90* angle to the wind shield opening, with your friend following along applying pressure exactly opposite you on the outside, all the way around.

As the rope is pulled out, it pulls the inner lip of the gasket up and over the pinch weld, installing the windshield.

Once installed, rinse off thoroughly and then apply clear silicone based calk all the way around the outside lip between the gasket and pinch weld.

I have done literally hundreds like that both professionally and in the back yard and have never had one single leak. Ever.