if a simple nock up and down does not work try this.
1. get behind the wheel and actualy saw it off (only on some cars)
2. get a pipe like the ones found on a building site and put it round the ignition bit and jump on it. this will snap the lock.
3. pull off the cap of the ignition and use a screw driver to get it off.

do u want to no how to disable alarms aswell lol?