1. 1. Find "Carrier"
Slide two fingers downwards starting from the top of the screen.
Press the settings icon.
Press SIM card & mobile data.
Press the required SIM.
2. 2. Select network manually
Press the indicator next to "Auto-select".
Press Off to turn off the function and wait while your phone searches for networks.
Press the required network.
3. 3. Select network automatically
Press the indicator next to "Auto-select" to turn on the function.
4. 4. Return to the home screen
Press the Home key to return to the home screen.