Dial the existing combination on your Star Floor Safe and remove the door from the safe. The order is four times to the left for the first number, three times to the right for the second number, and two times to the left for last number, and finally slowly to the right until you can turn no more. An error has been made if the dial doesn't stop.
Examine the door and locks for anything that might cause the lock system to not move smoothly. Wipe clean and lubricate if necessary.
Dial the existing combination to the change mark found to the right or left of the opening mark on the dial. Stop at the third number.
Insert the change key into the key hole on the front of your Star Floor Safe. If the key does not go in all the way, you may have inadvertently bumped the dial to a wrong number. Repeat if necessary.
Turn the key to the left one quarter-turn. This will free the dial/wheels from the existing combination.
Dial in your new combination beginning with four turns to the left, stopping at the first number.
Turn the dial to the right, stopping at the second number on the third time around.
Turn the dial to the left again to stop at the third number on the second time around.
Turn change key to the right one quarter-turn to lock in the new combination. Remove the key and store in a safe place.
Test the new combination using the opening mark on the dial before you return the door to the safe. Return the door to your Star Floor Safe and lock.