So there's a few on here, but I haven't seen this particular one yet to enlarge a hole that's in the right spot. Here's what you need, a hole that needs to be bigger. A hole saw that's the size of the current hole A hole saw that's the size of the hole you want A shock stud, same thread as the hole saws. Thread the shock stud into the larger of the hole saws first, then thread the smaller one on, this is the pilot. Chuck it up in the drill of choice and have at it. Works like a champ. The plywood outer pilot trick wasnt cutting the mustard on this one.