Skrillex doesn't spin live. Most big name producers or DJ's don't spin live. One reason is that too much cash is on the line for them to **** up. If you did want to do Live dubstep, you have to create loops and samples with each part of the song. Like a drum loop, synth loop, vocal sample, and bass loop. And trigger them using a Maschine, Launchpad, MPC, or something like that. There may be other ways, but That's one way.