A device for re-keying a lock that frees the locksmith from having to handle individual tumblers. A magazine is provided for each tumbler in the lock. Each magazine is numbered or coded to indicate the size of the tumblers within. The magazines fit into the top of a housing that temporarily holds the plug portion of the lock to be re-keyed. Upon alignment of the magazines with their corresponding holes in the plug, the tumblers fall into place and the lock has effectively been re-keyed. The plug is then removed from the housing and ready to be placed back in its original lock assembly.