Ask your attorney to file a petition and order for expungement, Judicial Counsel Form CR-180. You can do this yourself, actually, although your attorney will probably have a better shot at succeeding. Here's the link: http://www.courtinfo.ca.gov/forms/fillable/cr180.pdf.
There's a $60 fee, payable to the clerk of the applicable court. If you do it yourself, be sure to serve the prosecutor, and to add a certificate of service to the form you file with the court.
The forms used in Orange County are found below, along with instructions. You can do this yourself or with the help of an attorney.
The fee is actually $120.00. The $60 fee referenced in a prior answer applies to misdemeanor convictions, not felonies.
Best of luck to you --