I first removed the old paint completely with paint remover. I used Tuff-Strip, any heavy duty paint remover will work. Some say use Acetone but I never could get to work like I thought it should. After removing all the paint, give it a bath with Acetone. Using Testors paint, fill in the number/name with the color of your choice. I let this dry overnight, When dried the next day, put some Acetone on a rag, I use a tee shirt, and lightly go over the area you painted leaving the paint in the number/name. If you mess it up, just start over taking the paint off with the paint remover. Really pretty easy. With the paint remover and Acetone you should wear some rubber gloves and use both outside.