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

Captain, before you install that side glass check to make sure the curvature of the glass matches the original. I have found that some of the aftermarket glass is flatter that the originals. This causes the glass to bind up in the window channel. One fix to this is to file the plastic guides down to roughly half their thickness. This will it to slide in the channel a lot easier yet the glass still stays firmly in place.

Thanks for all the tips, guys. I was able to remove the blue rivets & will check with Chrysler tomorrow on the plastic liners. Also, now that I have all the hardware off the glass, I can check the new glass against the originals for curvature, etc.