How to remove windows?

I am doing rust repair on my 69 Bay. I want to remove all the windows and windshield to repair and replace the window seals. Someone told me that if done wrong I could break the windshield. Is there a tool, or a fool proof way of doing this?
Do you guys recommend coating the window channels with RUST BULLET?
Thanks

i usually just take a razor blade and cut the front part of the seal off, since your are replacing the seal. just push the razor in between the window and the seal. cut all the way around the window, and keep a small amount of pressure on the window so it does not fall out and break. once you cut the front part of the seal off you can get someone else to push from inside and you can gently take the window out.

Sounds easy, Thank you very much.

no problem, just let me know if theres anything else i can help with.