Get a glass form a salvage yard. No reason to hillbilly it up with lexan. The glass is easy to remove and replace. To take it out, start at the upper rear corner. It's more than a 90 degree angle. Pull the rubber gasket down and out. working toward the front and lower rear. The old one is good learning exercise - you don't have to worry about breaking it. There are two 8 mm nuts on the pillar trim that are accessible by removing the coat hook and something else.
The glass goes in and out with all of the trim attached. Star putting it back in at the rear corner where the sharpest bend is. You need someone to hold it from the outside while it's loose.
Actually if you get the glass, it shouldn't cost that much to have a pro install it. When I had my car painted, I got the windshield, quarters, and back glass removed and reinstalled for $200.