Yes. An entire will can be revoked at any time by destroying the original document, making a new will revoking the previous will, or by written direction signed by the maker and witnessed by at least two witnesses. You can also change parts of a will by making a codicil. This is a document that must be executed with the same formalities as the original will, and it may explain, modify, add to, subtract from, qualify, alter, restrain, or revoke provisions in a will.
In addition, some changes to your will may occur due to events in your life. For example, a divorce removes a former spouse from any role as executor and removes any right to inherit. Also, children who are not provided for in a will who were born after the will was executed can claim their share of the estate as though the decedent died without a will.