There is a lever on the back of the lock cylinder that actually binds the mechanism in the door. Another part of that lever assembly closes a switch that locks the central locking controller. If you can drill out the lock, you can dislodge these components and then unlock the doors from the trunk. The switch is what keeps the door(s) other than the drivers door from unlocking. My son's 87 325is driver's side lock is only there for looks, the lever assembly broke and therefore the whole lock is useless. He just locks the car from the trunk.