do what the homies above posted.
book the room now with the ap rate.
only a certain % of rooms and types are open for ap discounts.
once they are gone, you can not get that discount on your room.
once you check into the hotel, redeem the ap voucher for pass.
in your case, use your ticket to get into the park and upgrade it at guest services.
(or use the outside gs window.)
show your ap when you buy merch or food for the 10% discount.
if asked, show the ap to the front desk lobby once you have it.
do this sometime during your stay and before check out.