From a Home screen, swipe up from the center of the display to access the apps screen.
These instructions only apply to Standard mode and the default Home screen layout.
Navigate: Settings > Connections > Mobile networks.
Tap Network mode.
Select the appropriate setting:
Automatic: This is the preferred setting for most locations to allow your phone to automatically select the appropriate carrier and should only be changed if experiencing service issues.
Manual: This setting should only be selected if experiencing service issues in locations that offer multiple network types.
You can manually select an alternate carrier but it may require as many as 6 registration attempts with that carrier prior to successful registration.