It's a handy thing to be able to set your combination on your gate lock or briefcase, but like a password, it's a good idea to change it occasionally, especially if you've let anyone else know what it is. Some locks require a special reset tool that is supplied when you purchase the lock; you may be able to substitute a length of heavy-gauge wire if you've lost it. Other locks have an internal reset button that you can access when the lock is open.

Resetting Tumbler Locks

Step 1 Open the Lock

Open the lock using the existing combination. If you don't know the combination, there is no simple way to proceed; locks are designed to remain locked. Call a locksmith for advice.

Lift the shackle until the end disengages from the lock and swing it aside. If you're resetting a briefcase lock, open the briefcase all the way. If it's a cable lock, swing the cable out of the way.

Step 2 Locate the Reset Button

Look for the reset button on the lock body. On briefcase locks, it's usually behind or beside the lock. Some cable locks have a small reset button under the lock that you depress with a ballpoint pen. If you don't see a lever, the reset function may be activated by swinging the shackle 90 degrees from the closed position and pushing it down as far as it goes. If you don't see a reset button, you need a reset tool.

Step 3 Insert the Reset Tool

Insert the reset tool into the lock opening and push it down all the way. If you don't have a reset tool look inside the opening and note the size of the small hole inside. Find a piece of wire that fits exactly inside this hole. You'll need wire about the same gauge as coat hanger wire.

Step 4 Set the New Combination

With the reset tool in place or the reset button depressed, rotate the barrels on the lock until the numbers of the new combination align with the arrow. Release the reset button or remove the tool. The combination is now reset.