Activate the Shadows of the Empire debug mode.
Turn on "Villains are sleepy" in the debug menu. Now, go see the chicken walker dude. He'll be "asleep". Now, get your jetpack with the "get all items" cheat and fly up so you're facing his head. Shoot his head a couple of times and his head will magically disappear. However, if you turn "villains are sleepy" off, he will wake up with his head back.
Submitted by: kornyhatemachine