Place the briefcase right side up and set all dials on the lock to 0.
Place the safety pin into the slot to the right of the left dial.
Rotate the left dial slowly until the safety pin falls into an indent on the shaft. If you look between the left and center dials, you will see a square notch. Write down the number on which the dial is stopped.
Repeat this process for the remaining two dials until you have three numbers.
Attempt to open the briefcase by pressing the button beside the combination or sliding the lever to the side, which will release the latches. If it does not open, proceed to Step 6.
Looking at each number displayed on the dial, subtract 5 from each number greater than 5 and rotate the dial to that number. For instance, if the dial on the left is displaying 9, rotate the dial to 4, because 9 -- 5 = 4.
Add 5 to each dial that is set to a number less than 5 and rotate the dial to that number. For instance, if the number 1 is set, rotate the dial to 6, because 1 + 5 = 6. After the dials have been added and subtracted, the resulting numbers will be your combination.