A:AnswerIdk why no one answered you but if you can do it through your phone provider or Apple. I used the tmobile as an example because im going through the same thing lol so I broke my screen and since I have apple coverage they directed to Apple and they set me up an appointment at Best Buy to get it fixed
A:AnswerGo to your account settings, then go under menu look for support then go to plans and subscriptions scroll down to the Apple Watch and it should say update payment method :). Hope this helps