Block the exits and fill the holes with water. Forget the 55 gallon drum; use a hose if you can.

Woodchucks are decent eating, if you want to do that.

I can think of all sorts of traps, deadfalls, snares and suchlike that should work, but I'm not going to describe them here. Take a stroll down to the local public library and check out the books on wilderness survival techniques.

Might be easiest to pay an exterminator, though.