1. Find "Mobile & SIM"
Slide your finger downwards starting from the top of the screen.
Press All settings.
Press Network & wireless.
Press Mobile & SIM.
2. Turn data roaming on or off
Press the drop down list below "Data roaming options".
Press roam to turn on roaming.
Press don't roam to turn off roaming.
3. Return to the home screen
Press the Home key to return to the home screen.