You can't, race is 'human' and i dont think you can change, however you can change your class (paladin, ninja, etc) by speaking to various NPC's and learning there class.
No, you cannot change your race. Why would you want to? You're perfect whether you're black, white, Asian, or a mix of different races. You are you for a reason.
Class changes are not possible in World of Warcraft at this time. If you want to change your race, you can only choose from races which have your current class available. For instance, if you are a...
You can change your haircut from any shops with thescissors on the door, and if you have a dragon amulet go to popsprocket for exclusive haircuts, as for armour if you have a dragon amulet, click on...