For the fingerprint scanner to operate, hands must be clean and free of moisture, dirt, oil, lotion, dyes, etc.
Up to 4 fingerprints can be registered on the device.
From a Home screen, navigate: Apps > Settings > Lock screen and security.
If prompted, enter the current PIN, password or pattern
Tap Add fingerprint.
Locate the Home button below the display and place your finger on the sensor until it vibrates then lift.
Repeat this step as necessary until the process is complete.
For greater accuracy, finger placement should vary slightly each time.
If presented, choose what to display on the lock screen: