Just call the tracking world number and tell them what's happening, he will either guide you directly on phone or give you a contact number for engineer, who can do a simple guidance over the phone and your nav would start working without need for wifi.
I just did it last week, but don't remember the steps sequence that I went thru. Took less than 3 mins over the phone.
From memory, click the apps button on home screen, find the settings icon. In settings, find the Navi button, click that, find the TW (tracking world) maps button and click / high light that. Come back to main home screen and click navi now and than it should work. If not call the TW number on the card that came with car!