I've had my top replaced on the 78 and paid someone else to do it for exactly the reasons you've listed. But the guy came to my house and changed it in my driveway, so I was front & center for the whole performance. When I replace the top on my 75 I'm doing it myself. There's one area that's at all tricky and that's the front bow. Unlike the back and sides, there's no seam or marking to tell you where it has to go. I watched the guy do it and I won't even hesitate. If I'd just dug up the nerve to even try it myself I wouldn't have had any problem doing it. Taking the old one off told me everything I would have needed to install the new one.

And if what I suspect is true - that I'll be able to do a better, more careful, more detailed installation than the guy I hired bothered to do - I'll be replacing the soft top on my 78 again. He didn't properly line it up to the bows, he didn't properly line up the seams on the sides, he didn't measure the cable from the rear bow to the bow at the top of the back window. I wasn't at all happy with the way it turned out. By taking my time and paying more attention to the details than he did, I think I'll get a better looking and longer lasting install.