The new feature of Android Device Manager lets you override any password (PIN, Pattern, Face Unlock) on your Android device, remotely with a new specified password.
Do as follows to override password, in case you have lost your device or has been stolen:
1. Open Android Device Manager in a desktop browser
2. Click on Lock button
3. Type the new password, confirm it, and save the process
4. Your device is locked immediately (immediately after it gets internet connection) with the new password and you need to reset this password after your device is found.
Note that, You must had done the following to be able to use Override Password feature:
1. Open Google Settings application on your device
2. Tap Android Device Manager
3. Make sure "Allow remote lock and factory reset" is checked
See: How to Find Lost Android Phone with Android Device Manager