My question involves name change laws in the State of: Florida
My son is 4 years old. His father and I were never married and paternity has never been established in court (no child support or visitation). I desperately tried for the first 3 years to make him be a part of his sons life, but to no avail. At this time he hasn't seen or spoken to his son in 1 year and 5 months. He occasionally sends me random text messages to call me names, etc. He has told me on more than 1 occasion that he has no intentions of ever paying child support and has no interest in being in his sons life. The random times he texts me he's never once asked about his son or even mentioned his name. I have screenshots of all the times he's said he wants nothing to do with him.
When he was born, his father and I were living together. When he was 3 months old I had to flee due to his fathers severe alcohol abuse and growing abuse towards me. Anyway, I gave my son his last name on the birth certificate and his father signed the birth certificate also. At this point I want to change my sons last name to my own. Not to close any door on his father at some time making the right decision to get clean and come around, but because since he's not around, it would be easier for me to have the same last name as my son. I don't know where his father lives and the last time I actually spoke to him on the phone (almost 2 years ago), he told me he's living in NC. I've recently asked him for his address via text (he won't answer my phone calls) and he's refused to give it to me because he knows I'm asking for court reasons.
So my question is this: I know that if I have contact with him (or at least have a phone number) that I need to have him served, however I can't serve him because he refuses to give me his address. I've tried to find him online, but searching his name for the entire state of NC has given me nothing. So how do I go about this? What is a judge going to say when I tell him that yes, I have a working phone number for him but no, I didn't have him served because he won't tell me where he lives. Promise! lol Do I just use constructive service, post it in a newspaper and be done with it? I'd like to do this without paying for a lawyer because the process itself is pretty cut and dry. I guess I just would like some opinions on if constructive service, along with my explanation to the judge of these circumstances, and print outs of the texts refusing to give me his address will suffice? I don't want to spend the money to file and everything else only for the judge to tell me I didn't do enough.
Thanks for any feedback!

