If it is about the change of your username, theymos can do it but he has done it for only well established members before. Members that are having low rank may not be able to have that benefit. But even if you will have the benefit, it may take time. I remember how it took people like The Sceptical Chymist a very long time before theymos changed his username. But my advice is that you should not have such in mind until you ranked up more and become well established.
Theymos has changed the username of a newbie before. He did it because it was related to privacy. I think the newbie used the combination of his name and surname as his username. So, it all boils down to the severity of your reason for name change.