Quoted from Gornkleschnitzer:
Do I need to present any information (print a ticket or something) to get the game bringer two-day pass or is that automatic when I bring in the game?
When you show up with the game, someone will check you in and give you your wristbands for Saturday, Sunday and the after party.
They also give you a card for your game, so no one else can leave with it. Don't lose it.