How can I cange my user name?

[mesersmithi]

I wrote mmy user name wrong and I really need to chenge it.
I make my account with mesersmiti user name, and i need to chenge it in mesersmith.
Or, if this it can't be done, how can I use the same email address? It didn't let me use the same adress to make another account.

 

[mesersmith]

I succed to change my email adress. Thanks.