1. Turn Samsung Galaxy S5 with a card not accepted by the device, ie another operator (if the card has no PIN to enter it).
2. The phone should request the unlock code.
3. When prompted for the unlock code (unlock code or network code or nck code) you must enter the NCK / Network code and press OK.
!!! Sometimes the NCK code does not work !!! In this situation, you need to enter Unfreeze / Defreeze code and press OK (appear "wrong code") and then enter NCK code and press OK (displayed "correct code").
4. The phone is already released.