The phone lock code prevents others from accessing the contents of your phone (such as pictures and messages). When the phone lock code is turned on, it needs to be used every time you turn on your phone and when it has been in sleep mode.
Press Settings.
Press Security & privacy.
Press Lock screen password.
Press Set lock screen password.
Press CHANGE UNLOCK METHOD.
Press Pattern.
Slide your finger across the screen to connect at least four points, repeat the selected phone lock code and press DONE.
Press the Return key.
Press Lock screen password.
Press Disable lock screen password.
Key in the current phone lock code and press OK.
Press the Home key to return to the home screen.