1. Go to the mall.
2. Park in a congested area.
3. Lay down at the rear wheel of a car with rear drum brakes.
4. Take their bleeder cap.
5. Wash, rinse, repeat according to the number of wheels your bike has.
6. This also works for valve stem caps.
7. If caught, say that you dropped your keys. Keep them handy for proof.
8. If you actually do this, you are a douchebag.