Purchased an 88 Winnebago 22rb last year. The two front bunk windows were cracked and needed to be replaced. Local glass dealers wanted $100 / window for safety glass -- went to Home depot and purchased 2 sheets of their heaviest plexiglass ($16) - make sure it is same thickness as original safety glass, carefully removed one window and used it as a template to cut new windows (you can use a good jigsaw with fine blasde -- use paper protection on glass. I had to sand the edges to get a good fit but the rubber gaskets on Winnebagos are super tough and last a lifetime. The hardest part was fitting the new glass into the gasket & metal frame - make sure the gasket completely surrounds the plastic before fitting into metal frame. I would also recommend taking the metal frames completely out (vs. just replacing the glass) - it will be must easier to work with and by now the gasket material fitting to the camper skin is probably failing - use a good butyl compound and that seal and use abit of silicon once you fit the new glass in the frame. I've had no leaks and it has not pitted at all after 2,000 miles though it will be more prone to that over time, but worth the $$ savings.