After entering a pattern incorrectly 5 times, tap Forgot pattern?. Note: The device must have already been associated with a Google account for the 'Forgot Pattern' option to display.
To unlock with a PIN, tap the PIN field.
Enter the chosen PIN, then tap Done.
Tap OK.
Tap the desired option to reset the screen lock.
To unlock with a Google account, tap the Username field, then enter the Google account email address used to set up the device.
Tap the Password field, then enter the account password.