Joined: Nov 2016
He will *have* to drill it if the tumblers have fallen out and are all jammed up. Once they fall out, then you can use the paperclip in the hole to turn it and get it out properly.
I've spent about 10 minutes looking for a good picture, and to my shock and surprise, I can't find any useful ones either. But here's what I'd do:
1) Buy the new tumbler assembly. When you take it out of the box, it should have some paper instructions with it, hopefully including illustrations - but additionally, it will let you see exactly what the inner workings look like, and let you figure out how deep to drill. The length of your key will also give you an exact depth. No longer than the teeth on your key, basically. You could put a bit of tape on the drill bit so you know when to stop.
2) I'd start with a 1/4" drill bit, and run it down the 'top' of the hole, so it's chewing right through the already damaged tumblers and their holder assembly. With luck, they'll all fall out, which will then allow anything to freely turn the ignition switch, including a screwdriver. Once you can turn it, then you can use the paperclip to turn it to the 'removal' position and take it out without damaging the switch and "barrel" that holds your tumbler lock assembly. If it doesn't do the trick, you can go to a larger bit. Just be sure to go slow, don't press too hard, and have a good grip on the drill so it doesn't jerk out of your hand or wander around. You don't want to break off your bit in the lock.
Worst case scenario though - you buy a new lock AND barrel, and just replace them both. =)
I smile a lot. It makes people wonder what I'm up to...