Rear window rust repair without welding

You could cut out all the rust , fabricate all new metal pieces needed, clamp them in place then find a "buddy" to stop over with his welder and zip it up in an hour or two. I would do it for you if I was closer.

That is how I do it but I do own the welder. I just can't weld but I can always find people who can but have no welder.