Cracking your old Sentry Safe (without destroying it)

A friend of me lost the combination to his safe and asked me to open it. I like a challenge so I gave it a try, with success: an open safe and a retrieved combination. This video describes my approach to open the Sentry Safe by John D. Brush & CO Inc. Rochester, New York U.S.A.

If you lost the combination and you want to get it open again, this video might be the solution to your problem.

PS: i changed the current combination of this specific safe, so the combination in the video is not valid anymore.