Step 1: At the Mos Eisley Cantina, enter the following two codes:
CL4U5H (for Santa hat and red clothes)
and TYH319 (for white beard Extra).
Step 2: Go to the Character Customizer and create the proper costume. Use a human head, the red shirt, arms and pants and the black belt, cape and hands then select the red cap! Santa can wield the weapon of your choice I recommend the purple lightsaber
Step 3: In the Extras menu, activate Disguise 3.
Step 4: Enter the level of your choice in Free Play.
Step 5: Spread holiday cheer to a galaxy in pieces.