As long as you are alive, you can update your will. If your changes are relatively simple and can be clearly stated, you can use a codicil. A codicil is a new document that you would attach to your existing will that states the changes you want to make. Like your will, you and two witnesses must sign your codicil. If the changes you want to make are more extensive, or you want to avoid any possible confusion, instead of using a codicil, revoke your current will and make a new one.