The main thing to know is that preparation is key. Make sure the surface has been properly scuffed and is very clean. Then just use a high quality paint.
have the right paint the numberof the paint should match the frame number remove all scratches dents dust from handle , hang handle on a wire/string and paint completely
Make sure to use a few coats of primer, water sand it, followed by wiping it down with a tack rag. In a clean room spray your paint, allow to dry, then water sand and end with a polish.