Wait until you receive it, then call apple care and they'll help you out. Reason I say wait until you get it is because they'll need your serial number.
the store I went to turned me away because I didn't have an appointment.
They were extremely busy catching up what they did over the weekend.
The same person that blew me off so he could talk with this friend ended up helping me at the appointment. He looked at the sensor, looked at the phone and registered it. Less than 5 minutes.