Open the safe using the existing combination and remove the lid.
Remove the plastic cover on the back of the lid to reveal a set of numbered screws.
Use the tab on the plastic cover to spin the bolts to the right until they snap upward. Numbers in the combination should be turned to the right. Spin numbers not in the combination down and to the left. The code should be between four and seven digits.
Replace the plastic cover and test the combination with the safe open. Only replace the cover when you are sure the combination works. Check that the bolts are all turned left or right; the safe will not work if the bolts are pointing upward or down.