ATTENTION! This method is impossible if your hands are at your back with the keyhole facing away, as is the case when a law enforcement officer makes an arrest.
Watch the video to see it in action.
Step 1: What You Need...
1. I used a pair of police grade, Smith & Wesson Model 100 double lock handcuffs. This Instructable may also work on other brands so test them out.
2. One ordinary bobby-pin. Remove the plastic end.
Step 2: How to Do It
Bend the end of the bobby pin and put it into the key hole.
Take it out, and bend it the other way. and you should end up with an angle shape shown in the picture.
Step 3: Unlock the Cuffs
Insert the bobby pin in the keyhole. On the very edge, take the bobby pin and bend it down This will release the latches that will open the jaws of the handcuffs. If you have a double lock, put the bobby pin in the keyhole on the other side, release the double lock, turn it around to release the latches and open the jaw. You've just amazed your friends and audience!