You would still need to file a petition for name change and give notice. In your case probably notice by publication. Odds are pretty high though that you petition will not be denied.
Yes you can. Whose name is on the child's birth certificate? You will need to file a name change petition with the Superior Court in order to do a legal name change. You will also need to do a publication in a legally certified court newspaper. There will also be a court hearing. Feel free to call my office for a free consultation. You can also call the Superior Court in the county you live in to obtain more information.
20955 Pathfinder Rd., Suite 100
Diamond Bar, CA 91765