It pulls off pretty easily, but you never know what you'll find underneath. I took mine off when I was restoring the car 15 or 16 years ago and got lucky. There was just a bunch of old glue under the top. No big deal since I was having the car media blasted at the time.
I wound up not putting another vinyl top on it because I like the cleaner look without it. I saved the trim pieces in case I ever change my mind.
One way or the other though, even if you find rust when you pull the top off, it would be something you would want to address anyway I imagine.