Entering the incorrect unlock pattern 5 times will cause pattern reset options to display.
Tap Forgot pattern.
To unlock the device with the established backup PIN, tap the PIN field, and enter the required backup PIN.
Alternatively, enter the email address and password for the Google account linked to the device. Note: The device must have already been associated with a Google account for the 'Account unlock' option to display.
Tap Sign in.
Tap the desired screen lock type, then follow on-screen prompts to complete setup.