Samsung Galaxy S4
1. Dial *#0011#
2. press Menu then tap BACK
3. press the Menu again the tap KEY INPUT then enter 1, press OK button
4. press Menu then tap BACK
Your are now in the SERVICE MODE MAIN MENU
Tap [1]UMTS
then [1]DEBUG SCREEN
then [6]PHONE CONTROL
then [6]NETWORK LOCK
then tap [3]PERSO SHA256 OFF
Go back to the UMTS MAIN MENU by pressing Menu then Back then tap [6]COMMON
then [6]NV REBUILD
then tap [4]RESTORE BACK UP
the device will freeze, black screen, Blue LED Light, Menu and Back key ON. Wait for it to reboot (about a minute).
Your Samsung Galaxy I9505 is now Sim-Unlocked.