1. Girlfriend or wife who isn't afraid to use a clipper outfit.
2. Start with the biggest guide attachment. Do the upper parts of your hair with this and BE CAREFUL NOT TO PRESS TOO HARD, OR YOU WILL KNOCK THE GUIDE OFF AND GIVE YOURSELF A GIANT "OOPS." Gradually change to smaller guides as you go around your head until you achieve the desired length.
3. Barter with a friend who will trim your hair in exchange for a barter item.
Is it possible, that you know of, to accidentally cut the hair shorter than the length of the attachment? Like stick on a 3/4" attachment, push at the wrong angle and get a 1/8" patch?