3 quick problems

You could drill out the lock but... Once you remove the latch and lock from the inside you can bolt the latch back in place. Then you'll operate it with a flathead screw driver through the lock hole until a new lock cylinder or key comes along.
Right now a locksmith can cut a key or rekey that lock cylinder. Once its drilled its trash.
would a locksmith be able to rekey it while it's still intact and in the car? That above all else would probably be the easiest and least painful scenario. I didn't think that could be done but if it can be ...