I live in Louisiana when my child was born a boyfriend signed as the father on her birthcertificate. Later we found out that he isn't the father. Now I'm wanting to change her last name to MY last name, how can I do this.

Get his permission.File Petition for Change of Name/usually in Probate Court/

§4751. Petition for name change; adults; minors

C. If the person desiring such change is a minor or if the parents or parent or the tutor of the minor desire to change the name of the minor:

(1) The petition shall be signed by the father and mother of the minor or by the survivor in case one of them be dead.

(2) If one parent has been granted custody of the minor by a court of competent jurisdiction, the consent of the other parent is not necessary if the other parent has been served with a copy of the petition and any of the following exists:

(a) The other parent has refused or failed to comply with a court order of support for a period of one year.

(b) The other parent has failed to support the child for a period of three years after judgment awarding custody to the parent signing the petition.

(c) The other parent is not paying support and has refused or failed to visit, communicate, or attempt to communicate with the child without just cause for a period of two years.

(d) The other parent has refused or failed to visit, communicate, or attempt to communicate with the child without just cause for a period of ten years.

(4) The petition may be signed by either the mother or the father acting alone if a child has been given a surname which is different from that authorized in R.S. 40:34(B)(1)(a).