1. Sand the decals down with an automotive Scotch-Brite pad or 800 grit sandpaper.
2. Clean them thoroughly with mild detergent, rinse, and dry.
3. Tape off the edges with green detail tape first then blue painters tape and finally paper.
4. Apply a base coat of primer either by spray or roller. Keep in mind the wrong nap roller can produce an orange-peel finish! The primer coat is designed to fill in cracks. Do very thin applications several times allowing proper drying time. You can use commercial-grade spray paint such as Rust-Oleum or Krylon.
5. Sand the primer with 1000 grit sandpaper between coats and clean with paint thinner.
6. Spray or roll desired paint color with several light coats and let dry properly between coats.
7. Spray several clear coat applications after the paint has dried properly.
8. Remove the tape and paper carefully as the paint could start to peel between the tape and part of the unit you want painted. Go slow. You may need to use the sharp knife to help keep the edge you want.

Decal maintenance

The bottom line in keeping your graphics/decals looking good longer is protecting them from the harsh UV rays of the sun.

This can be done by covering the unit when not in use, positioning the rig in a direction that keeps the sun away from it during the hottest parts of the day, or looking at UV protection products. As mentioned before, 303 protectant is a good product as well as Protect All and a good wax that has UV protection.