You have to contact their customer service. They walked me through the steps but I don't remember them all right now.
The Gabb watch is completely bare bones. It's glitchy. But all we wanted was a way to see where the kids were when they weren't with us, and for us to be able to reach each other. It serves that purpose. I have a month to month plan and got the watches free during a promotion. I'd be mad if I actually paid for them.