What does my son need to do to get his name removed from a birth certificate of child that is not his?

Is there already a court order adjudicating your son as the father? If so, he would need to file a modification and serve the mother and the biological father. If not, he would file an original suit affecting the parent-child relationship and serve the mother and biological father and seek a court order excluding him as the father and naming the other man as the father.