Tamashii Nations just announced the procedures required to purchase the five SDCC Exclusive figures at the event. It looks like you need to show up at the Dragon Ball booth in Marina Terrace to get your ticket on the morning of each day to get your reservation ticket, which will show the time you can proceed to the Tamashii Nations booth in the convention center to purchase your exclusives.
There is also a no ticket purchase at the end of each day where you can just show up to purchase what is left of the remaining stock on that day. This sounds like a overly complicated way of doing this. The old version of purchasing online and then picking up at the event seemed more user friendly.
Also, there is no word if these figures will be available for pre-order on Premium Bandai after the event, but lets hope it is!
Check out the following link for exact details!