Working with a sunroof is always a PITA, so keep that in mind. Also, you're going to need the headliner with the sliding sunshade, so figure you'll likely have to remove the windshield or rear window during the process and transfer that large, fragile item. But the actual glass/metal panel swap should be relatively simple.

I'd like to do this to my wife's '93 940, but the headache/benefit analysis does not yetmake sense...