Under California Civil Code section 3154, an owner can petition the court to remove a stale mechanic's lien. The court is authorized to award attorney's fees of up to $2,000 to the prevailing party on the petition. My suggestion to you is to hire a lawyer who has experience with mechanic's liens, and have the lawyer write a letter to the contractor, telling the contractor that he either records a withdrawal of lien, or you are going to file a petition, get your attorneys' fees, and then make another claim on his bond. Most of the time, the letter is all you need.
The Ventura County Bar Association can help find you an attorney who can assist you. The link appears below.