I pulled my Spyder windshield just a couple of months ago (first time) and I cracked it, but it was my own fault for being impatient. I went around initially with a heat gun to soften up the seal, then used a sharp utility knife from the outside. That was a good start, but then I used an oscillating tool with a staggered flat blade and it made EASY work of removing the windshield seal. My mistake was in getting impatient in not waiting until I got ALL the way around the windshield before trying to pry the glass way from the car. Be careful here, because it is VERY brittle, so even "taking a peak" by prying up a half inch or so from one corner caused mine to crack down the middle.
Ironically, once I finally used the oscillating tool all the way around the windshield, cutting through the seal, I was still able to easily remove the windshield in one piece, even with the 'top to bottom' crack in it.
'78 C06 Monza Spyder