Question: how to change a child's last name in nh?
Answer: Step 1 – Complete Petition. Download and complete the New Hampshire Name Change Petition, making sure to select the “Minor” checkbox at the top of the form. ... 
Step 2 – Complete Assent Form (If Applicable) ... 
Step 3 – File Forms. ... 
Step 4 – Attend Hearing (If Applicable)