Probate Code § 6120

A will or any part thereof is revoked by any of the following:

(a) A subsequent will which revokes the prior will or part expressly or by inconsistency.

(b) Being burned, torn, canceled, obliterated, or destroyed, with the intent and for the purpose of revoking it, by either (1) the testator or (2) another person in the testator’s presence and by the testator’s direction.