My question involves name change laws in the State of: TN

I need to find out how to file for a name change without a qualifying event like marriage or divorce. I went to the courthouse and was told to file a petition with the clerk's office. Easy enough except when I asked if the petition needed to be filed as a letter or a form, the only information they gave me was to look up the T.C.A. I can't find anything in the T.C.A. that tells how to do this. There is a sign in their office that says they do not endorse nor accept online forms other than official state of Tennessee forms. Still no help because I can't find an official form for this. Can someone tell me what exactly they are needing for a petition? If it's just a letter to the court requesting the change and why, I can do that. I only want to do this once and not have it rejected for not being in the correct format.

Thank you in advance.