The diving itself is simple -- click to jump out of the airplane, hear the same silly "yeeeehaw" soundbite whether you're the male or female diver, then use a right-mouse-click to go from a spread-eagle position to a tuck, move the mouse left and right to perform various tricks, and finally click the spacebar to pull the ripcord.
The researchers got some brave specimens tomove a mouse cursor by implanting plastic pads containing electrodes underneath their skulls, with the sensors sitting on the surface of the brain.