1. Find "Network operators"
Slide your finger down the display starting from the top edge of your mobile phone.
Press the settings icon.
Press Network & Internet.
Press Mobile network.
Press Network operators.
2. Select network
To select a network automatically, press Automatic.
To select a network manually, press Search networks 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.