Newer cars require windshields to be glued in to provide structure (eg. rollovers) and prevent egress through front during crash. And the air bag uses the windshield as backing.

Butyl is easy to cut through with wire.

Poly urethane has to be cut through with a knife eg. box cutter from the inside. Oiling the poly (eg. WD40) speeds the slicing but it still takes time. Flexible putty knife (1 to 2 inches wide) helps.

There is a windshield removal tool (Princess Auto in Canada so probably Harbor Freight in US) with a strong handle and puller and a right-angled blade that slips under windshield and cuts. But I had trouble getting it to cut even with a lot of tug (Didn't want to risk breaking windshield).

You could have saved that '84 windshield. A razor blade paint scraper removes stuff off glass effectively.

Polyurethane takes a while to cure, so avoid driving for 24 hours (sudden stops may pull windshield away). Use duct tape to hold windshield in place until dried.
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1980 245 Canadian B21A with SU carb but electronic ignition and M46 trans in Brampton, Ont.