Turn off face matching
1. Go to Settings.
2. Touch Security > Face unlock.
3. Unlock your phone.
4. Touch Delete face data.
Fix an issue
If you're having trouble getting the phone to recognize your face:
1. Go to Settings.
2. Touch Security > Face unlock.
3. Unlock your phone, then touch Redo face scan.
4. Set up face matching again.
Settings : Security : Lock and unlock phone 247