When your new husband begins the adoption proceedings of your son, you would file a Petition to Terminate Alleged Natural Father's Parental Rights. Your ex-husband would be given notice of the proceedings and if he fails to appear or fails to claim parental rights, his parental rights will be terminated.
It's not quite as easy as filing a petition that goes unopposed, as was indicated above. If you both are in agreement, then a petition or motion can be filed completed with a stipulation. However, if the petition simply goes unopposed then you are facing an uphill battle. I would highly suggest you speak to an attorney in your area who has experience in this area.
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