Remove the pipe from the bike and take off the end cap. Using some 400 grit sandpaper, smooth down the area where the paint is peeling. After the surface is smooth, use some 600 grit sandpaper to rough up the entire surface (Scotch-Brite works OK too). Buy 1 can of high temp, BBQ or ceramic paint of your liking. Tape off the sections you don't want painted and apply several light coats of paint until it is covered and even. Allow the paint to dry thoroughly before ridding.