Is it possible to change the combination on lock boxes that have tumblers or keypads?
You can usually change them when the box is open; for instance, if you want to deny access to someone who has the current number. If the box is locked and you’ve forgotten the number, you’re going to have difficulties. You can try contacting the manufacturer, but even if they have a way to open the box, they can’t tell you via email or phone. They wouldn’t have any way to verify that you have authority to open the box.