Changing the "Preferred Service Center" entry in the app is easy. You can also keep more than one listing in this virtual phone book (but only 1 can be your preferred center).
Tap on the "My RV" field at the bottom right of the screen OR the "Set a Preferred Service Center" near the bottom of the screen IF you haven't set up a center yet.
Tap the lime green plus sign near the bottom of the page to add a service center
Enter your details, then toggle your "Preferred Service Center" over from Gray to Green. Or just leave the Toggle gray if you do NOT want this entry to be your preferred center and simply want the info close at hand.
If you wish to edit your "Preferred Service Center" simply tap on the lime green arrow on the right and then the pencil that pops up. You can edit the entry or delete it if you prefer!