Duster Quarter Window Popout window seal replacment advice

I have the rear pop out windows out of my '74 Duster. I ordered the replacement weather striping seals from Steele Rubber. They are supposed to be delivered today. Has anyone had any experience replacing these?

I was looking at the pop out windows last night and it looks like they are riveted together with a few LONG rivets. I don't really want to go cutting away on rivets that I can't replace.

Has anyone ever replaced these seals before? :help: