I have a steel door in which I'd like to replace the deadbolt lock with a newer keypad type lock. The door is a bit older and the hole is 1 1/2 inches. The keypad deadbolt requires a 2 1/8 inch hole.
I've created a guide out of plywood as described in this thread and I have it lined up as best as I can. My question is, do I go all the way through to the other side of the door in one shot? Or do I do one side, then move my guide and try to line it up on the other side door?

