My boyfriend signed the birth certificate and we did a Legal DNA test through DNA diagnostic and found that he is not the biological father. I determined how to change my sons last name, but I do not know how or what to file in order to remove him as the legal father from the birth certificate in the state of oklahoma. Tulsa, Oklahoma. PLease help me!!!!!!

You will have to file for an amendment - the Court Clerk who assisted you in changing his name should have all that info. If not: Oklahoma Birth Certificate, Death Record, Marriage license and other vital records (http://www.vitalrec.com/ok.html)