A will, or any part of it, may not be revoked in a manner other than as provided in this section.

            (1)      By provision in a subsequent, validly executed will which (i) revokes any prior will or part of it either expressly or by necessary implication, or (ii) expressly republishes an earlier will that had been revoked by an intermediate will but is still in existence;

            (2)      By burning, cancelling, tearing, or obliterating the same, by the testator himself, or by some other person in his presence and by his express direction and consent;

            (3)      By the subsequent marriage of the testator followed by the birth, adoption, or legitimation of a child by him, provided such child or his descendant survives the testator; and all wills executed prior to such marriage shall be revoked; or

            (4)      By an absolute divorce of a testator and his spouse or the annulment of the marriage, either of which occurs subsequent to the execution of the testator's will; and all provisions in the will relating to the spouse, and only those provisions, shall be revoked unless otherwise provided in the will or decree.