If you forget your pattern:
1. After you fail to unlock the screen in pattern for 5 times (4 dots at least), there will be a text sign of "Forgot Pattern?" appeared on the lower-right of the screen.
2. Tap "Forgot Pattern?" and then enter your Google account and password saved in this phone to disable pattern lock.Note: If you do not log in your Google account or the device is not connected to internet before the phone is locked, you will need to perform factory data reset in DROIDBOOT mode to solve this problem.
If you forget your PIN or password:
1. To reset your PIN or password, you need to in advance log in your Google account in your device and have your phone connected to Internet as well as Location function enabled.
2. Then, visit website below: https://google.com/android/devicemanager
3. Choose your device that you want to reset PIN. After your device is located, tap "Lock" in the wondow and reset your PIN.