If you made a new thread you can report your own old thread and ask for deletion. If you have not made a new one yet, you can report the old one to ask for a title change by a mod.
This is not advice for regular use. You can do this as an exception as it's normal users still learn they way around the Lorwolf forums, but in the future I suggest using the title it should have right away & putting “WIP” in big letters at the top of the first post! <3
Edit: After discussion with the team - if you need something renamed, rather than opening a report send a private message to a forum moderator such as myself, with a link to your thread and the new title.