This article describes how to reset a pattern lock.
INSTRUCTIONS & INFO
After 5 failed unlock attempts, tap Forgot pattern?.
To unlock with the backup PIN, enter the PIN, then tap OK.
To sign in with a Google account, enter your Google login information, then tap Sign in. Note: The device must have already been associated with a Google account for the 'Account unlock' option to display.
From this screen, the screen lock method can be adjusted.