Door Glass Replacement Question - 69 B-Body

I'm putting new side glass from ECS in my 69 GTX & have a problem I'm sure others have faced. The glass is fastened to the window channel with a blue-colored plastic rivet that doesn't want to come out & probably won't want to go back in on the new glass. And, I don't find a source for the new rivets.
What's the preferred solution here? Trim the rivet enough to get it out, then glue it back in? Try to find a nylon bolt & nut that will work as a replacement? What's worked for others?
Also, on the subject, what are people using as replacement for the plastic liner that fits on the vertical part of the glass inside the vent frame? Anyone reproducing it or do I need to reuse the old, which is not in good shape?
Any insight would be appreciated.

The liner that goes in the vent frame is still sold by Chrysler. It comes in a kit for one window and includes the plastic retainers that hold the glass in the frame. Legendary also sells them @ around $40 per side(their part #WS66CBVENT). I think R/T Specialties sells the blue rivit-like fastener, but I could be wrong.

put a socket under the blue rivet and use a punch and tape the centre it will come out and you can reuse it

Quote:

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put a socket under the blue rivet and use a punch and tape the centre it will come out and you can reuse it

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The rivet is a two piece unit and you need to push out the center that locks in onto the window.. Push it out, remove and install rivet on new glass, and then push the center of the rivet back in it......