I did a 68 Camaro vinyl top with my brother years ago. No biggie.
I didn't do my '69 myself. I started to do it, but I got scared that I might not get it just right. I'm a perfectionist by nature and defer to others
when I'm not up to the challenge. The areas of concern to me were around the window trim ( front & rear ) and how the vinyl top tucked
under it so as to eliminate peeling and the trim seating properly.
I did wet sand the top paint up to the area where the vinyl top chrome would be installed. This promoted better adhesion of the glue.
BTW, as I didn't have the trim location anymore, so I had someone with a vinyl top car under restoration send me the measurements for each
rivet location on the quarters and the back ( below the rear window ). Drilling that first hole was scarry.
Once I started drilling, it get easier
with every hole.