It's actually really easy in the M3 because it's so balanced and that LSD works so well. It's just like on the snow except you are going a lot faster and have to be more aggressive with the steering and throttle inputs.
1) flick the car slightly the opposite direction of the turn (if you are turning right, slight flick to the left) - this loads the outside tires more dramatically.
2) turn in too much
3) use too much throttle, but not too too much. You have to use just the right amount of too much throttle.
4) use too much throttle and too much steering angle to hold it (steering angle back the *other* way after it starts)
5) push in the clutch and brake when you spin
6) figure out some sort of legitimate explanation for event organizers for your hoodlum behavior
7) video the whole thing and post on youtube.com, yo boieee