Punch in the existing numerical combination and open the safe door. You should always have the door open when you change the combination. Make sure that the locking bolts are extended before you proceed.
Enter six zeros into the combination. This will put you into the programming mode, which should be signaled by two beeps.
Enter the existing combination. This will be followed by a double beep of affirmation that the safe is ready for proceeding. Then enter in your new six-digit combination. This also will be followed by two beeps. Enter your new combination a second time; this also will be followed by two beeps.
Wait roughly 10 seconds or so. Put in your new combination and turn the handle. If you put the combination in correctly, then the handle will turn and your new combination is officially in the system.