Find "settings"
Press the phone icon.
Press the dots in the bottom right corner of the display.
Press settings.
Turn on divert
Press the indicator next to "Call forwarding" until the function is turned on.
Divert calls to voicemail
Press the field below "Call forwarding".
Key in (prefix) 5 (your phone number) and press save.
Return to the home screen
Press the Home key to return to the home screen.