A codicil is a separate document you use to make changes to your original will. If you want to remove a beneficiary, you may use a codicil to change the part of the will that lists that beneficiary. Laws for codicils vary by state, but you usually must clearly identify the original will's date, what you are changing in the will and your new terms. You must sign the codicil in most cases, and you may need the signatures of one or more adult witnesses as well. You may attach a codicil to your original will; if your codicil is stored separately, there's a chance it will be overlooked after you die. An error in your codicil, or in its creation, may render the document useless in court. If you're making major or several changes to your will, a codicil may not be the most appropriate option for you.
You may make a new will entirely to change your beneficiaries. The new will must conform to state standards and you must follow all legal requirements, as you did with the previous will. Often, when a person makes a new will, she includes a statement that says she's revoking all prior wills; this means the new will and its terms will replace any older wills. If you make a new will, tell your executor and a trust family member of its location. If no one knows about your new will, your old will may be presented in court instead.
If you make a new will to change beneficiaries, but the new will doesn't meet your state's standards, your state's intestacy laws will determine the distribution of your estate. Intestacy laws don't take any of your wishes or your heirs' needs into consideration. Although the laws differ by state, your spouse and children are usually the first in line to inherit your estate. If you don't have children or aren't married when you die, your estate may pass to your parents or siblings.
You might not be allowed to disinherit your spouse or your children in your will, depending on your state's laws. Some states provide automatic estate shares to spouses and children, regardless of what you leave to them in your will. The American Bar Association doesn't recommend altering your original will by crossing out provisions or writing over words. Whether you're allowed to alter your original will by hand depends on your state's laws and the requirements for such alterations. Even if your state allows alterations by hand, the court must decide whether you made the changes to your will yourself and interpret what you meant if you write in new provisions or remove existing lines.