How can a mother remove the father's last name from birth certificate?

I have had cases like this. Although it is time consuming it can be completed. It is necessary to have a judge approve a notice of service of a complaint for change of birth certificate or name change by alternate service. If approved this allows the service by publication in a daily periodical that is accepted as a place for legal notices in the county of his last known address. But first you have to provide what is known as an affidavit of due diligence, usually provided through a private investigation service that checks for addresses throughout the US by social security number, date of birth, drivers license # and/or other identifiers. Once an affidavit is received that no address can be located and that he is likely not in the country, a court will usually permit alternate service. Another method I have used when the other parent knows of family members in the other country is to actually try and get information from them (if they are willing to share). Be advised though that service in a foreign country can be a tricky affair as some recognize the same forms of service we do (registered mail or personal service for instance) if they have signed the Hague Convention treaty on that, while others do not. Sometimes it is necessary to get an attorney involved in the other country. But the easier method is if you can get service by publication of legal notice here in N.J.