You can't sorry
Type /goto username
Username change hasn't been implemented into the game servers yet. Will probably in future tense, most probably.
how to change your glogster username
You can't change your username on WoozWorld.
You can't yet change your name in AQWorlds. The moderator's are deciding rather they should update it so you can or not.
probibaly not but you can try. I have a firend that is lvl59.my username is horussoul and my pass is blood (this is a lvl40 by the way!)
No, but you can change the capitalisation, for example; If your name is 'username', you could change it to something like 'UsErNaMe'.
you can't ..
You can't.
You can't. when you choose your username you can't change it.
You can't change your username!
You can not change your Moshi Monsters username.