Find "Network operators"
Slide your finger down the display starting from the top edge of your phone.
Press the settings icon.
Press Tethering & networks.
Select one of the following options:
Select network manually, go to 2a.
Select network automatically, go to 2b.
2a - Select network manually
Press Search networks.
Your phone searches for networks within range.
Press the required network.
The display will tell you if you have access to the network you've chosen.
2b - Select network automatically
Press Select automatically.
Return to the home screen
Press the home icon to return to the home screen.