1. Find "Carrier"
Slide your finger down on the display.
Press the settings icon.
Press SIM card & mobile data.
Press the name of the SIM.
2. Select network
To select a network automatically, press Auto-select.
To select network manually, press Auto-select.
Press Off 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.