Joined: Feb 2006
Posts: 571
Likes: 0
From: Canberra, Australia
Bikes: Salsa mtb * 3, Intense mtb * 1, Abeni SS rd * 1, Salsa road/touring * 2, Trek Damn one * 1, Vintage/projects * many
A chisel is probably a bad idea, especially if it's your father's chisel. Screwdrivers make good flat punches, I have a couple which are specifically for use as punches for things like this. Don't forget it's reverse-threaded so turn clockwise to undo.
Joel