my son’s last name is hyphenated with his fathers name and then mine. He is two now and it has been 1.5 years since his father has seen or tried to see him. He hasn’t even spoken to him in 6 months. With him starting pre-school next year I would like to drop his fathers last name out of his name since he resides with me 365 days a year. I have sole physical and legal custody of my son. His father has zero rights or visitation. can I do this?