Drilling through wasn't much of a problem, the hard part was getting rid of the little pieces of metal left over... A hand file, using an old screwdriver as basically a chisel, and trying to grind a little with the side of the bit (the bit was already pretty chewed up) took a little while. I'd recommend using a dremel or regular drill with an aluminum oxide bit or something if you don't want to spend about an hour on this.