When real estate in California is owned by joint tenants and one of the owners dies, the remaining owner(s) can clear the title by recording an affidavit of Death of a Joint Tenant.
Joint tenancy is a way for two or more people to own property in equal shares so that when one of the joint tenants dies, the property can pass to the surviving joint tenant(s) without having to go through probate court.
The affidavit should be recorded in order to be binding on others. Take a certified copy of the death certificate of the deceased joint tenant and your affidavit to the recorder's office in the county where the real property is located.
Deeds.com California Affidavit Death of Joint Tenant Forms Have Been Updated as Recently as Thursday April 19, 2018