Find "Data service"
Press Menu.
Scroll to Settings and press the Navigation key.
Scroll to Network and press the Navigation key.
Scroll to Data service and press the Navigation key.
Turn data roaming on or off
Scroll to Data roaming and press the Navigation key.
Scroll to Off, National roaming only or All networks and press the Navigation key.
Return to the home screen
Press Disconnect to return to the home screen.