68 Trade Wind Small Lower Window Removal

[68 TWind]

Hope someone can give me advise on how to remove the bottom windows on my 68 TW. I got new curved glass from Andy @ Inland for the top and replaced the smoked plexiglass. Looks great and now I need to get the small rectangular flat lower windows out. I drilled the rivets out on both sides on the inside (3 on each side). I can put a putty knife along the edges, but it will NOT push inward( has to come out that way). The gasket material is old and hard and I don't want to cut it due to impossibility of finding replacement to fit in the grove. I am at my wits end on this one, anyone who has replaced a lower window and can help will be a hero!

Thanks in advance,

Bruce