Just use a magnet. If the magnet doesn't work, go and purchase a rare earth magnet. If you don't want to purchase an expensive rare earth magnet, go to a friends place and (when he/she) isn't looking, rip their hard drive apart and steal the (impressively powerful) rare earth magnets out of the drive mechanism.
Sure, they might scream and yell that their life collection of precious family photos are destroyed, but just remember that motorized bicycling is of far greater importance than inter personal relationships.
You can be sure that (after many months or years) they will get over their grief - maybe...
