After seeing how easy it is to get Kensington keyed notebook locks open, I am switching to a three-number Kensington lock for my upcoming trip...but I can't figure it out (bought it a few years ago and discarded packaging). It has a flip switch on the bottom with red and green markings on either side, and a green mark on the side where the numbers line up. How do I set it? Cannot find instructions on Kensington site. Also have a 4-digit Defcon lock, much easier to use, but it won't be back in the office until after I leave, and I'm gone 6 weeks. Thanks!