Forgot password
I forgot password for 1st gen AirPort Extreme
iPad (3rd gen) Wi-Fi + Cellular (VZ), iOS 6.0.1
If you have a Mac you can use this procedure to extract its password from Keychain: Can you help me with my Wifi password?
If you don't have a Mac, "soft reset" the Extreme by depressing its reset button momentarily. The Extreme will lower its shields for a two minute period, in which you can use AirPort Utility to configure a new password.
Don't press the button for more than a second, otherwise you will need to reconfigure it completely.