To change your name legally as an adult in Massachusetts, you need to go through a court name change proceeding. First step is making sure you have ORIGINAL (stamped) copies of your birth certificate and any other relevant records.To change your name and gender marker with the Social Security Administration you need to fill out an. Application for a Social Security Card16,17. To change your name and gender marker with the Social Security Administration you need to fill out an Application for a Social Security Card. What is the best way to approach this situation? This form is available here for download. Pick a first choice name and a second choice name. Fill out the Planning Board's "Way Name Change" form. Your name change petition should be filed to a Family and Probate Court in the county where you live.