My son's father has not seen him for over 5 years and has not tried to make any contact with him. My son is 10 and we have lived in the state of Texas for over 5 years. My son's father lives in Connecticut. He has not paid child support within that time. My son wants to be adopted by my husband. My husband has supported my son for a while now and his father has not had anything to do with him. What can I do?

None of those facts change the process. You still have to file a petition with your local Family Court for him to adopt. As part of that petition the bio father will need to be contacted and sign a relinquishment of parental rights in favor of your husband.

If he refuses to sign, it is possible the court will override his objection given the that he has made no attempt to be a part of his son's life.

I would not try to do a step parent adoption without an attorney. So your first step is to shop around for one. If the bio father will agree to it, then it should be simple and inexpensive.