You can do it with a razor blade and a lot of patience, or as the author shows, using a small pipe cutter that you could easily get into the airport with a carry-on.
He shows this in the Fragguccino video (http://www.youtube.com/embed/TZ5a4ycwsig): by using a small pipe cutter (on a lithium AA battery). He notes that it can be done without the pipe cutter but would take more time.