After entering the wrong pattern for 5 times, tap OK. Note: The Forgot Pattern option will only display if you have added your Google Account to the device.
Tap Forgot Pattern. Note: The device must have already been associated with a Google account for the 'Forgot Pattern' option to display. If your Google account was not added, you must do an alternate factory reset of the device. Search tutorials for ‘reset’ for Reset Device instructions
Tap the Username field, then enter the Google account used to set up the device.
Tap the Password field, then enter the required password.
Tap Sign in.
The lock screen has been reset. Tap the desired option then follow on-screen prompts to set up a new screen lock.