There are a few ways that you can remove graffiti from a metal door. The first way is to use a power washer. You will want to set the power washer to a low setting and hold it about two feet away from the door. Spray the door in a back and forth motion until all of the graffiti is gone.
The second way to remove graffiti from a metal door is by using sandpaper. You will want to start with coarse sandpaper and work your way up to finer sandpaper until all of the graffiti is gone.
The third way to remove graffiti from a metal door is by using chemicals. There are many different chemicals that you can use, but you will want to test them on a small area of the door first to make sure they do not damage the finish. Once you find a chemical that works, apply it to the graffiti with a cloth and rub it in until thegraffiti comes off.