That's been my experience too. Of course, they usually pull the glass and put in a new one but if the shop's any good they'll handle your request w/o hassle. If the shop is NOT any good you don't want them anyway!

The reason it's so hard to get these out - they're held in with a REALLY tough adhesive (no, it's not RTV like bathtub caulk) that was especially invented for this. I'm not sure if they were the first but Morton Thiacol (sp?) was early in this game and the adhesive is often called "Thiacol". Remember, the glass is expected to stay in place even in the even of an accident. They went to this because the glass stays in place better and is much less likely to leak though of course everything ages.

Anyhow, the only way to get these out is to cut ALL THE WAY THRU the adhesive which is not as easy as it sounds. The pros have an assortment of tricks and tools to get this done including a heated knife that is often pretty helpful. I've bought some of the tools but still had mixed results and I decided that it was cheaper to have the pros do it if the glass was worth saving.

EDIT: The best paint durability requires that the windshield and back glass are out anyway. It's the only way to clean and get paint into the window channels which will protect those areas against rust. If you pull the trim and try to paint up to the glass the rust WILL come back. So you're doing the right thing!

Dan