Prepare, or have your attorney prepare, a codicil, or amendment, to your Last Will and Testament. Keep in mind that a codicil must be properly witnessed, attested and acknowledged in the same manner as your original will. The codicil will state that you are omitting or revising that particular paragraph that mentions the person you are excluding. You may want to make it clear -- even by leaving him $10.00 or some other small amount as his final share -- that you are intentionally excluding him. You may also recite in your codicil, if you desire, your reasons for omitting the person. Some state laws will not allow you to disinherit a spouse totally by use of a will or codicil alone. A marital agreement signed by both husband and wife, however, may allow his or her omission from the inheritance.
Prepare an entirely new will if the changes you are making are substantial enough to require it. For instance, if the person you are omitting is the only devisee under your old will and you are adding a new devisee to replace him, then it would be preferable to destroy your old will and have your attorney prepare a new one. It would be advisable to make sure that not only the original, but also all copies of your former will are destroyed to prevent someone attempting to probate it in place of your original will.
Divorce your spouse. A divorce may not entirely invalidate a will; however, in many states, it will remove the former spouse from any provisions of the will as if she had predeceased the Testator, or will-maker. Many states require that a couple be separated for one year before filing for divorce. You should use caution if you are in this situation, as barring a court agreement to the contrary, the spouse may still inherit under your will during the separation period.