You have to DJ low enough that your DJ would end slightly above the stage. When I've done it without an aerial, I don't know if technically my DJ would've ended there anyway, but I kinda just slide onto the stage without landing lag. It's really hard to explain, but the best way I can describe it is that you sort of slide over the lip of the ledge and end in a stand or a walk.
(You've probably done it before and just didn't notice. I dunno if it's related to the fair thing, but it seems like it could be.)
With an aerial, I'm guessing it's similar except that he started Pika's fair slightly before he "slid" into the stage so that it autocanceled when he hit the ground.
EDIT: I'm about to head out to dinner, but I'll try to recreate it when I get home if y'all haven't already. Remind me on AIM!