How should I prepare the surface for the decal?

How should I prepare the surface for the decal? Please read these instructions all the way through before starting your application. The surface must be clean, and free of all oils, waxes and dirt. If decal is to be applied to GLASS, use Windex or a comparable cleaner to clean the glass. If you use RainX, try Formula 409 to remove it. On painted surfaces wipe with a wax remover or alcohol if applying on freshly waxed paint. These Decals come to you in three layers. The top layer is called the Transfer Tape. It looks somewhat like regular masking tape. The middle layer is the actual Decal. The bottom layer is a Backing Paper treated with a release agent.