How do we go about doing this?
He never signed my sons birth certificate and never paid any child support. My son is 14 now and wants to be my fiancés son.
He (my fiance) has been the only father he has ever known since he was 8 weeks old.
Also my sons biological father was very violent towards me and my son and my 2 children from a previous marriage.
We are not rich people and do not have a lot of money so how can we go about doing this?:o

how do we go about doing this?
he never signed my sons birth certificate and never paid any child support. My son is 14 now and wants to be my fiances son.
He (my fiance) has been the only father he has ever known since he was 8 weeks old.
Also my sons biological father was very violent towards me and my son and my 2 children from a previous marriage.
We are not rich people and do not have a lot of money so how can we go about doing this?:o
I think you are going to need an attorney. Try this web site.
FindLaw: Legal Services Resources (http://www.findlaw.com/14firms/legalaid.html)
Or contact your local law enforcement agency, they will be able to help you.

Let me know.

You are going to have to go to family court and see of the court will take away the biological fathers rights, even though he is not listed he still has legal rights as the father

There may be a legal aid society in your area. The social services agency in your area will know their contact them.

If the bio father will just sign over those rights, it will be much easier.