Find "Change Passcode"
Press Settings.
Press General.
Press Passcode Lock.
Press Change Passcode.
Change phone lock code
Key in your current phone lock code.
Key in a new phone lock code.
Key in the new phone lock code again.
Key in a new phone lock code.
Key in the new phone lock code again.
![Apple iPhone 4S iOS 5 Apple iPhone 4S iOS 5](http://wmstatic.global.ssl.fastly.net/ml/7290921-1802708.png?width=480&height=480)
Exit
Press the Home key to return to standby mode.