How do I replace these metal pieces from my instrument panel?

Yes. What were you using the first time? 95/5 copper pipe solder? (Not well designed for electrical if so, you'd need flux and lots of practice, as the size is just too much to manage).

BUT, as others have said, the strength comes the mechanical staking operation. Attaching w just solder, and it will break again after a few potholes. I'd send it to Mike.
I will try to get Mike to repair it. Thank you.