As others have said, you can book a reservation online using your AP. You have to have registered your AP on the website already.
1. Go to the Disney website (waltdisneyworld.com)
2. Sign in (upper right corner) - the new page requires you to verify information for your account and accept the terms & conditions. Hopefully you only have to do this once.
3. Under MyDisneyExperience click on "Annual Passholders"
4. Click on "Passholder Resort Special Offers"
5. Click on the link for the offer you're interested in and then about half way down the page you'll see a link for "Check Availability" or "book online". You can use those to book your trip.
These are the steps I used just now to make sure you can still make an online reservation given the new webpage design. Things might be different if they tweak the site (again). Good luck!