Each user has a username (which they log in with) and a display name (which everyone can see). By default these are the same.
In this thread you can request a change to either or both. Note that changing your username will
reset your password, and send you an email containing your new password. If you don't receive this email, check your spam folder.
If you just ask to change your "name", it will be assumed you mean both.
For clarity, post both your current name and your new name. I.e.
Please change my name from mister_walrs to Mr. Walrus
Name changes should be restricted to fixing capitalisation and typos. Requests to change to a completely different name will be ignored unless you've just registered.