Instructions
Start the Avatar Editor from the main menu of your Xbox 360. The Avatar Editor is found by navigating to the "My Xbox" menu, then to your profile name, under "Customize Avatar."
Click on the Marketplace tab in the Avatar Editor. This takes you to the listing of all available Avatar clothing and props. Scroll from "Lifestyle Collections" into "Seasonal Collections" and finally into the "Halloween Classics" menu.
Scroll through the magical costume and prop items. Highlighting an item demonstrates how it will interact with your Avatar. The wizard-themed gear from the "Halloween Classics" collection includes the "Wizard Hat," "Wizard Costume" and "Flying Broom" prop.
Click on an item and spend the necessary amount of Microsoft Points to download it to your storage device. You will need to have Microsoft Points tied to your account or a credit card to purchase predetermined amounts of Microsoft Points to buy and use these Avatar items.
Equip the clothing and props in the "My Style" section of the Avatar Editor once they have downloaded to your Xbox 360. Use the "Save and Exit" button from the Avatar Editor's main menu to save your preferences and return to the Xbox 360 main menu.