Hi John,
The rear quarter windows are held in by a rubber flap over a short piece of body metal surrounding the entire window opening. A small amount of careful prying on the rubber (from inside the engine bay) and pushing on the window will result in the entire assembly moving enough where you can then pull the entire window (gaskets + frame) from the outside.
Keep in mind they're easier to remove than to put back in. So once I pulled mine out, I just left them out.
Josh
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