The project: replace a broken wing window + frame.

Old one's out and the frame and such are about to be POR-15d. The pop rivets broke so it came out in two pieces -- one through the top and the other below.

Question: is it possible to get a complete wing window assembly (frame, glass & seal assembled) back in -- without prying open the top opening? It looks like the top opening would have to be bent .5" which I'd rather not.

What's the best way to get it back in?

john