I assumed these were like a sticker? You could just apply like you would mylar?

Yes they are on clear background.

So you take your tray, sand back, repray, allow to dry.

Then take the decal and apply, place soapy water and that allows the decal to slide to the desired position

Have emailed Lee today to ask on the progress of Pinball Rescue and will release all details here at AP

Might sound like I'm pushing their product but they are first class and make your games come alive 

The more we support them the more products they make for the hobby