I just replaced the driver side window regulator. I bought these tools from Harbor Freight and they made the job way easier. I didn't break any of the panel clips. The mirror cover pulls out at the bottom and then slides up the pillar to release. I ground off some of the burrs on the pliers and then wrapped the working end with electrical tape to help prevent marring. I wished I had these pliers 30 years ago. I have used the plastic tools for all sorts of prying and adjusting.
Panel Clip Pliers
5 Piece Auto Trim and Molding Tool Set