If you can,how do you change your Username?

Can you change your username? If so,how? Cause I wanna change my name without having to make a different account.

Nobody on their own can change their own account name, but you can contact Lady Orihime and discuss the possibility for a name change with her. :) There might be special rules concerning name changes (I honestly can't recall if there are, but I don't want to get your hopes up just in case), but even if that's the case, she will certainly let you know.

Basically, you have to pay to change your name