My question involves name change laws in the State of: California
*last names have been changed for privacy.
My son has his mother's maiden name and my name hyphenated on his birth certificate. She has since married and had another child and has changed her name and NOT kept her maiden name(the one that is hyphenated on this birth certificate). I have also since been married and have had a child with my wife. I want my exes maiden name dropped from my sons last name and just have mine. As of right now, she keeps putting ONLY her maiden name on all his documents (school, doctors,etc..) not the complete hyphenated name or just my last name. She has even gone as far as to tell my son that, "If you want to, I can change your last name to your new daddy's if you want. That way you and Mommy and brother can all have the same last name too."
All out of spite.
He doesnt believe me when I tell him his whole last name. He thinks it is only *Smith. So he is very confused why his last name doesnt match EITHER of his families last names. I will NOT consent to have her change his last name to his step fathers name either. I have been his father and invovled with him emtionally,physically, mentally and financially since day one. BEFORE the paternity test was even done. Legal and Phycial custody is 50/50. I have never been late on child support or refused to pay it. I was paying it before it was ordered, MORE than what was ordered and I have the proof.
How do I go about dropping his mother's maiden name? So instead of
*Smith-Jones, it would just be *Jones. I would like to get this done as soon as possible, my son has started Kindergarten already and is very confused.
Thank you.

