Living Will, Revoking
A living will can be revoked, or cancelled, at any time, no matter what the principal's mental or physical condition is when making the revocation.  A revocation can also be expressed in any manner, even verbally, without a signed writing.

Any revocation is effective immediately upon its communication to a health care provider, who must immediately make the revocation a part of the principal's medical records.

See: Living Will, When Effective; Living Will, Who May Create; Living Will, Delivery