1. Find "Network operators"
Slide your finger down the display starting from the top edge of your mobile phone.
Press the settings icon.
Press Mobile networks.
Press Network operators.
2. Select network
To select a network automatically, press Select automatically.
To select network manually, press Select manually.
Press OK and wait while your mobile phone searches for networks within range.
Press the required network.
3. Return to the Home screen
Press the home icon to end the session and return to the Home screen.