It can be disabled quite easily. Press the button on the center dashboard labeled ESP. A bright triangle in the upper half of the speedometer will light up.
My question is: Why do you want to do that? If you run with the Electronic Stability Program off, the back end of the car will break loose on hard pavement when you accelerate aggressively. I've done it a few times, got to admit it's fun but you don't want it off normally.