I've done it. I had a '74 Swinger that was bubbling under the top at the quarter/roof seam on the c-pillar. It was an original car with the original top. As stated above, I carefully heated the top just enough to warm the metal and soften the glue a bit but not melt the vinyl. I was able to carefully peel it up above the seam far enough to grind and wire brush the rusted area and repair it.

I used por-15 on the metal, then filled the seam with fiberglass filler, and sanded and finished the area.I then heated the top and the vinyl again, sprayed the glue and stretched it back down. Still looked nice when I sold the car quite some time later.
Dallas