Things You'll Need
Instructions
Turn on your Xbox 360, then, from the "Spotlight" page, press up once on your controller. You should now be on the "My Xbox" page.
Press right on the controller to move over one tile; this tile should show your 3D avatar along with your Gamertag name. Select this tile by pressing the green "A" button on your controller.
Press down on your controller to highlight the second selection, "Profile." Select it with the "A" button.
Press down to highlight the second selection, "Edit Profile." Select it with the "A" button.
Press down once to highlight the second selection, "Gamer Picture." Select it with the "A" button. Choose the first selection, "Change Gamer Picture," by pressing the "A" button.
Choose the picture you want from the gallery of pictures. You can download more from the Xbox Live Marketplace. Confirm the picture selection by pressing the "A" button.