Obtaining a Certificate of Rehabilitation
A certificate of rehabilitation is a way to get a pardon and is available if you live in California. You would file a petition for this in the Superior Court. If this certificate is granted by the court, then it serves as an automatic application for a Governor's pardon.
In most instances, you must be a California resident for at least 3 years before filing. The certificate and the pardon will not remove the conviction or seal the records. You would still have to disclose a prior conviction on a job application.
However, you would still be allowed to serve on a jury. And there are cases where some sex offenders are dismissed from having to register.