Well... I'm a single mom and when I first had my son I didn't add his fathers name to the birth certificate nor did I want him to sign simple due to pure ignorance... but now that my son is almost 3 I want to give him his fathers last name and I want his fathers name to be on his birth certifiate as well... his father has been asking for that since he was born and I think it is about time to do so... how do I go about those changes?? /

First its not a good idea to piggyback your question on someone else's. This can lead to confusion. You should start a new thread. So I've moved your question to its own thread.

Since both parents are agreeable. It may be very easy. Contact your local bureau of records and ask what the procedure is. However, it may require going to court to have a paternity test done to get approval for the change.