73 Duster - how to removal rear windshield = want to reuse gasket and glass

Trim is off and the round lock bead is out. I don’t want to cut the gasket and/or break the glass, need to remove to perform repairs to trunk gutter and make it easier to reach top inner of quarter panel. Car is gutted, no trunk lid, doors, fenders, suspension, or other glass, it is presently a shell in process.

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