Mich. Comp. Laws § 556.218

Sec. 118. Unless the power of attorney provides a different method for an agent's resignation, an agent may resign by notifying the principal if the principal is not incapacitated or, if the principal is incapacitated, by notifying the following persons, as applicable: (a) If a conservator or guardian has been appointed for the principal, the conservator or guardian. (b) If a coagent or successor agent has been designated, the coagent or successor agent. (c) If there is not a person described in subdivision (a) or (b), 1 of the following: (i) A caregiver of the principal who is reasonably believed by the agent to have a significant interest in the principal's welfare or another person that is reasonably believed by the agent to have the significant interest. (ii) Adult protective services.