Find "Call forwarding"
Slide your finger down the display starting from the top edge of your phone.
Press Settings.
Press Settings.
Press Call settings.
Press Call forwarding.
Select divert type
The current settings are displayed.
Press one of the following options:
Always forward
Always forward
Forward when busy
Forward when unanswered
Forward when unreachable
Divert calls to voicemail
Key in (prefix) 5 (your phone number) and press Enable.
Return to the home screen
Press the home icon to return to the home screen.