Another will or codicil: under sec 18 (1) of the Law of Succession Act, the will or codicil revoking the earlier will must declare intention to revoke it.
Destruction: under sec 18 (1) of the Act a will is revocable by burning, tearing or otherwise destroying it with an intention to revoke it. Such destruction may be by the testor or some other person acting in accordance with the directions of the testor. A person can only revoke a will by destruction, if he has capacity to make it.
Marriage – Under section 19 of the Act, the marriage of the testator revokes the will unless the will is made with contemplation of a marriage with a specific person. Such a marriage does not revoke the will.