Select "My WWE" at the main menu, then "Options", followed by "Cheat Codes". Enter one of the following codes to activate the corresponding cheat function.

John Cena Street Fight gear and "Never Give Up" Avatar T-shirt
Enter SLURPEE as a code.

Randy Orton Alternate Attire
Enter apexpredator as a code.

Unlock the "Tribute to the Troops" arena
Enter 8thannualtribute as a code.