I have a busted rivnut/ bolt within my seat stay – I was wondering if there was a clever way of taking it out. I can pull it’s head out with tweezers (photo), but it doesn’t want to come any further. Anyone encountered similar?

It’s not even rattling around when riding, just want to remove it for my satisfaction really.

Glue.

Yep. Wot Al said. Don’t remove it, just get some Araldite in there and glue it in place to stop it rattling.

Fill frame with concrete to stop rattling!

(also helps improve your fitness….)