When I had my son who is now 8 months old me his father and I were not exactly on speaking terms. However times have changed and are better for all of us and his dad is very much back in the picture now. But my problem is that I gave my son my last name and now I want to change his name to his fathers last name but I'm kind of lost on how to do this

Both you and the father have to sign the petition to change a minor's name in the court of the county in which you reside, setting forth such desire and intention and the reason therefor.
A court order granting a legal name change should be sufficient to amend her birth certificate.

Does this mean that I don't have to go threw the ss office.. and fill out excessive amounts of paper work?

Which state?