Hold a free demo of the 3d technology in jackass 3d on the street. However the TV will not be a real TV. It will simply be stunt glass with the jackass logo on it. Or it would be better if you had a freeze frame on the screen of wee man with Preston behind him.
The picture would perfectly line up with the real background that is behind the actual TV. Put curtains up around the side so it looks more like a display.
Have everyone put on the 3d glasses.
Once their 3d glasses are on have Wee Man jump out of the fake TV and be running away from Preston.