Open VZAccess Manager.
From the Macintosh desktop, navigate Finder > Applications > VZAccess Manager.
From the Menu Bar, click Options > Network Selection.
Select the desired option from the Network Mode field.
If switching to GSM Mode, select the desired option from the Select network field.
If selecting Manual, ensure that the desired network is selected from the "Please select a network and click Register" field then click Register.
The network with the strongest signal is used.
A selected network will be used.
The preferred international carrier is automatically selected. You can manually tap an alternate carrier but it may require as many as six registration attempts with that carrier prior to successful registration.