I've always used the backing paper from my old check books. I take a very small ballpean hammer and lighty tap it untill I punch a hole then I install a screw to hold it in place. I then do the same thing on the far corner for another screw. Then I lighty tap around the inside to cut the gasket out. After I have it cut out, I install the back plate and then trim the rest off the outside with a #11 blade. I have done this for years and have never had any problems with it. I hope this helps.