Hi, and welcome!
What brand of safe do you have and do you know the model number?
Is it made by Sentry? If so, does it have a round or rectangular keypad?
Does it also need a key to get into the safe, along with the combination? If so, do you have the key?
Thanks for all your additional details.
Never mind! I figured out how to pull off the control panel and change the batteries.
Glad you were successful! : )