1 Find "Touch ID & Passcode"
Press Touch ID & Passcode.
2 Turn on use of phone lock code
Press Turn Passcode On and key in a phone lock code of your own choice twice.
3 Turn deletion of data on or off
Press the indicator next to "Erase Data" to turn on the function.
4 Turn off use of phone lock code
Press Turn Passcode Off and key in the phone lock code.
5 Return to the home screen
Press the Home key to return to the home screen.