1. From the home screen, tap the Settings icon.
   
2. Tap Lock screen.
   
3. Tap Select screen lock.
   
4. Tap Knock Code.
   
5. Tap Next.
   
6. Enter the desired knock code, then tap NEXT.
   
7. Re-enter the knock code, then tap CONFIRM.
   
8. Tap NEXT.
   
9. Enter the desired backup PIN, then tap NEXT.
   
10. Re-enter the desired backup PIN, then tap OK.
    
11. Tap OK.
    
12. To access the device using knock code, at the lock screen, tap the knock code sequence in the designated area.
    
13. To turn knock code off, tap Select screen lock.
    
14. Enter the existing knock code, then tap NEXT.
    
15. Tap the desired screen lock type.