Change your child’s last name by getting a court order, called a Decree Changing Name. When you show the school a Certified Copy of that Decree, they will change their records to show your child’s name exactly the way you want it. A judge has to approve it all and sign your court order, but you can do it. You just have to start the process, do it all correctly, and finish it.
You can do more than one child in a single Petition for Change of Name. And, the name change costs and process are the same, whether you want to change one letter of one name or every letter of every name. Once you get the court order, you can change your child’s social security records, all identification including their birth certificate if born in California.