How do you unlock the main pin screen lock on your LG H631/MS631

[AC Question]

Someone stole my phone and changed all PIN numbers and emails how do I get bk into the phone to use it I just got it back today it's an LG H-631/ms-631 g style

 

[the tall guy]

Hi, how did you manage to get it back if it was stolen? did the thief return it? have you tried Android Device Manager for unlocking the device?