Find "Settings"
Press the Menu key.
Press Settings.
Press Connectivity.
Press Settings.
Turn data roaming on or off
Press Allow mobile data usage.
To turn on data roaming:
Press Worldwide.
Press Worldwide.
To turn off data roaming.
Press In home network only or In home country.
Press In home network only or In home country.
Exit
Press the Menu key to return to standby mode.