One doesn't. We do not delete members, even at member request. If a member wishes to leave the TT we suggest they clear their profile of any personal information, put in false information for fields that cannot be left blank, and simply log out, never returning. Our rules, available at http://www.tickletheater.com/index.php?page=rules, describe our policy on member deletion.
If you wish to change your name we can do that; let me know what new name you would like to have.