Find "Mobile networks"
Press Applications.
Press Settings.
Press Wireless and network.
Press Mobile networks.
Activate or deactivate data connections
Press Use packet data to activate or deactivate data connections.
When the box next to the menu item is ticked (V), the function is turned on.
If you activate data connections:
Press OK to confirm.
Press OK to confirm.
Exit
Press the Home key to return to standby mode.