If you mean an AKA you added? Go to the "Manage Your gamerDNA
" from the drop-down menu at the top of the site. From there, select "Manage Your AKAs
" and you can edit, add new ones, or delete the old ones. Alternatively, you can just click on the links I've provided.
If you mean an X-Fire account, you'd have to go to their site to find that information. I don't use X-Fire (it doesn't run on OSX), so I'm not certain how one cancels their account. I would assume there would be a section to manage your account.