To do this is simple. For one thing, you must choose a wrestler that normally does a powerbomb or would do a powerbomb. Only one character i have found does a backbreaker off the side, Brian Adams. Powerbombers are Nash, Norton, The Giant, and i think Rick Steiner. To do this move, simply get on the side of the ring(outside the ropes), do a strong grapple, and then hit A or B. If it works, u will see the wrestler pull their opponent out onto the side, and then both will go down to the floor, one being put in this powerful move.