Auto body repair & detailing: vinyl top removel, rust buckets, cadillac sedan deville

Question
i have a 1977 Cadillac sedan Deville that has a old vinyl top on it the top is in good shape but I'm afraid that there is more rust under it than just what I'm seeing around the windshield. how do i remove this and is it possible to let it off and still have my rear window sealed or will i have to put it back on?

Answer
It's possible to remove the top and leave the rear glass in without removing it, or having the glass seal- but I suspect that once you remove the top, you will find rust around the lower rear window channel. 1970's Cadillacs were NOTORIOUS rust buckets. I would remove the entire top, and not put a vinyl roof back on it. Bill