If the change is minor, then they can do a "codicil", which is basically an amendment to a Will. However, if there are several change to be made or a major change is required, they should just have a new Will drafted. With either instrument, you will need to have 2 adult witnesses who are not beneficiaries of the Will. They can go online and find forms for the state in question; just pick a reputable site. Also, they can go to a probate attorney and have one drafted. As a compromise, they can fill out an online form and then have a have an attorney review it for them, which would be a cheaper alternative then having them draft it. Whatever they do, they must be sure that if a new Will is done (versus a codicil), that it revokes the original Will.