Although my safe is clearly not the same as yours, the lock mechanism is possibly similar and the following instructions may be helpful.
1. Open the safe – if you don’t know the current code then you can use the physical key (the keyhole is usually hidden by a cover that can be levered off.
2. On the inside of the door, towards the hinge, you should see a small red button.
3. Press this button until the yellow light on the front control panel lights up.
4. You can then input the new code (1 to 8 characters) on the front control panel, followed by the A or B key.
5. The safe should then beep twice to confirm that the code has been set.
6. If the safe beeps three times then the code has not been accepted and you must repeat the steps above.
Good Luck.