usual prep is nothing more than cleaning the glass with windex.

You will find that by trying to remove the tape you will probably take some paint with it. I may cut off excess tape that is just hanging, but I never added any or did any paint touch up.

Others may feel differently, but thats my way.

By the way, I support mirror clips all the way. Home Depot usually carries 2 sizes which you will need as some glass is thicker than others.

Take a picture when you have them hung as I would love to see them.

Doug