I have a black flip up keypad, wireless remote just outside the garage door. I have the current code, but need to change it with urgency.

There is no name, make, or model on the keypad - I bought it at home depot. It has 0-9 and an On/Reset button. The 9 volt battery goes in at bottom of keypad and slides up. Maybe someone recognizes this keypad brand - so if you don't know how you can tell me the brand and I can search online for instructions.

I really need to get this changed and have no idea how to change the code. Any help would be greatly appreciated.