My daughter is ten months old and her biological father and I are not together and never been married. We have not spoken since I left him when I first found out I was pregnant. My daughter has my last name and the father spot on the birth certificate is blank. My boyfriend however has been with me since I was three months pregnant and was there when she was born and has been her daddy ever since. I would like to give my daughter his last name and put him as father on her birth certificate. How can I do this?