Assuming it's booked under your name, which it would be, it's a breeze. I rented DVC points for my week long stay and at check in, you will be greated by a cast member at the entrance who will ask for your name under the reservation. Guys get the beaded necklace, ladies will get lei'd, and little kids will get a necklace with a menehune. Tell you a bit about the entrance and ask for a credit card and ID. From there, you have the opportunity to have the staff bring up your luggage to your room so you can walk around or go straight up there yourself.
Most people do not know, but as a DVC guest (rented or an actual DVC member), you can get FREE laundry. You are allowed 20 coins per day, just go up to the front desk and ask for the coins, they'll confirm you are in a DVC room, and give it to you. I've had so much coins left, I gave them to a lucky couple where their expression said "this place IS magical!".