Your will is not written in stone - for the most part
We are finishing up our discussion of the various ways a testator can change his or her will. There are codicils and separate writings, for example, that can amend or supplement an existing will. And, over the past couple of decades, technology has made it easy to execute a new will instead of tweaking the old one. In some cases, a new will may even be the more economical option. Ultimately, it is up to the testator: There is no right answer here.
There is, however, a right way. If you simply take a red Sharpie to your will and start crossing out names and adding new language, you risk invalidating the modified provision or even your entire will. That Sharpie mostly spells trouble for your personal representative and your estate after your death.
If you have extensive changes and opt to rewrite your will, you need to revoke the old one. Michigan law recognizes "revocatory acts," -- burning, tearing up, obliterating all or part of the document -- and allows the court to presume that the new will revokes all prior wills. The court may, however, determine that the new is a supplement, not a replacement. The court will also consider your state of mind at the time you made the changes, to make sure you were aware of what you were doing and not destroying the will under duress.
So, to avoid cost and confusion later on, the better choice is to include language in the new will that specifically revokes all prior wills and codicils. One sentence can be the difference between a valid and an invalid will. It can be the difference between a will sailing through probate and a will and estate being mired in litigation for years to come.
Again, your will and estate are unique. You may choose the Sharpie over the codicil. We recommend, though, that everyone considering amending a will or starting over from scratch consult with an experienced probate and estate planning attorney.
Source: Michigan Pleading and Practice (2d ed.), Part V, Chap. 99: Probate/Wills in General, August 2015, via WestlawNext