You can only reset a pattern lock, if you have a Gmail account set up. To unlock the pattern, follow these steps:
1. After five (5), ten (10), fifteen (15), etc. unsuccessful attempts at entering the pattern, you will see a temporary lock out.
Note: The option to sign in will not appear immediately on the phone. It only appears after multiple failed attempts to enter the pattern, and then is goes away after 30 seconds. If the option never appears, then the device does not have a google acount set up, and you must perform a master reset with hardware keys.