If the judge approves your request to change your name, you will get a Decree. That's the document you will use to change your name on all your legal documents.You are required to complete all applicable items before you will be issued an amended commission. 1. Print your full legal name – first, middle last. I'm 24 years old, not doing a gender-change but just wanting to change my first name and add a middle name (I do not currently have one). Fill out the petition for name change form with your new name and sign it. Have your signature notarized. Go to the courthouse and fill out a form, showing your current name and the name you want, plus your reason for changing it. Current last name of either spouse or the last name of either spouse given at birth. Obtain a paper form in the same manner as noted in the previous section.