1. Find "Carrier"
Press the Navigation key.
Select the settings icon.
Select Network & Connectivity.
Select Mobile network & Data.
Select Carrier.
2. Select network manually
If you want to select a network manually, select Automatic to turn off the function.
Select Off and your phone will search for available networks.
Select the required network.
3. Select network automatically
If you want to select a network automatically, select Automatic to turn on the function.
Select On.
4. Return to the home screen
Press Disconnect several times to return to the home screen.