BE VERY CAREFUL if you choose the converting tickets option. I've done it twice, both with kind of bad results.
The first time, I did it intentionally. We wanted one AP- for hotel discount (You don't need to buy them for everyone, if you just want room discount). We picked Epcot. Epcot parking doesn't have a 'drop off' area. I went in the park, and guest services accused me of stealing my ticket. They were not remotely nice. They didn't ask to see the paper receipt, and basically refused to convert the ticket. He almost refused to give me back my ticket!
I walked out, upset but knowing I was in the right. I went out the front gate to the guest services there. The second CM was nicer, and I remembered that I had taken a photo of my receipt AND that photo still just HAPPENED to be in my smartphone! It was my first trip with smartphone - and we brought both the phone and the digital camera. I left the digital camera in the car. Still, when he first tried to convert the ticket- he only offered me full price. (see below).
The second time I converted tickets, it was accidental. We decided to do a bounceback. Well, again- the CM only offered us full price- until I was slightly insistent. It took us OVER AN HOUR in the GS office to get our AP's!!!!!! It was ONLY with the help of a manager that it worked.
If you do this- MAKE SURE you know EXACTLY what it should cost. When
UT buys tickets, they don't pay full price- they pay a special bulk rate. So BOTH times- GS tried to quote the value of my ticket at that bulk ticket rate. They also buy tickets like a year before you buy them from UT. That's why they thought I had ill-gotten tickets. My ticket had been bought by UT over a year before I did.
The second price I was quoted also valued my ticket incorrectly, and would have negated the UT discount I'd gotten.
The best agents I have encountered over many trips, and numerous ticket issues over the last 15 years are at MK! that is your best bet, but be prepared to lose an hour (That can be a huge pain on your first morning!!!!) AND Make sure you have a copy of your proof of purchase, AND Make sure you know EXACTLY what you should pay.
A far simpler way to get 5% off your AP is to get a Target credit card. Buy Disney giftcards using your Target card. You can also get a second 5% if you use the Target pharmacy. Mark EACH CARD with a SHARPIE as you use it. If you are buying an AP using gift cards, just do it all at once.
During vacation though - it can be tricky and time consuming to keep track of the gift cards. They are best used all at once for big WDw purchases.