1. Find "SIM settings"
Slide your finger downwards starting from the top of the screen.
Press All settings.
Press Network & wireless.
Press Mobile & SIM.
Press SIM settings.
2. Select network
Press Search for networks.
Press the drop down list below "Select a network".
If you want to select a network automatically, press automatic.
If you want to select a network manually, press the required network.
Press OK.
3. Return to the home screen
Press the Home key to return to the home screen.