Never tried this on a B body, but I was able to make a long enough extension out of some flat stock to pop the lock from inside after I removed the rear seat in my old C body. I would also seriously consider getting a can of spray graphite lube for locks and try that before I drilled out my lock.
They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.
