Have Force Lightning ready, then open the door to where Skywalker is located. An intermission sequence will start. When it ends, immediately use Force Lightning on him and he will start attacking you or the Stormtroopers. Note: If done correctly, you should have him attacking you and the other Stormtroopers shooting at you simutaneously. If you take too long and you cannot use Force Lightning on him before he kills all the Stormtroopers, the Reborns will attack and Luke will not attack you as much.