Please choose a FAQ section:Adding wallpaper on your Profile
Click the "Home" tab and then select "Edit Profile".
Now on the far right hand side select "About Me". Below your entry box you can see a selector of all the available wallpaper. Once selected a desired wallpaper then select "Save" and then "Finish".
You will then be prompted back to your profile home, in the far right corner select "View Profile". As you now can see your new look profile!