Entry location: Command Post: Warehouse
At the Warehouse Command Post, go toward the ammunition droid and stand on it. Face the wall and go forward. It takes a couple seconds, and your character will start to jiggle. That is a sign it is working. At this time, you will be inside the little house you were facing, safe from all blaster-fire, but you will be able to shoot bullets through the wall (Hint: it is best to be either the Clones, or the Empire, because they start at that command post.) Also, if a Jedi Hero is activated, they can't come inside, so your pretty much invincible!