If you wish to stop a power of attorney you should sign a document called a "Revocation of Power of Attorney".

A power of attorney is a document authorizing another person, either a lawyer or non-lawyer, to act as your agent or "attorney" in fact. This differs from hiring an attorney as in that instance, you are asking that person to advise and represent you in legal matters. When you sign a power of attorney, you are permitting that person to act on your behalf in various situations, such as signing papers for you or taking care of your affairs. See similar questions...

Advance Directives are a legal document that describes the kinds of procedures you would want (or don't want) in the event that you are unable to communicate or make decisions for yourself. We recommend you appoint someone to speak on your behalf should you be unable to. This person is called a Durable Power of Attorney for Health Care. Please ask your social worker for these forms to complete. See similar questions...

Yes. You can have a living will and a durable power of attorney for health care at the same time. Generally you can provide additional instructions in your advance health care directive for situations to which the living will does not apply. It is important to ensure that these documents are consistent so that there will be no confusion concerning your wishes when you are unable to make them known yourself. Some states also permit you to have a single, combined advance directive document. See similar questions...

A Power of Attorney is a legal instrument that is used to delegate legal authority to another. The person who signs a Power of Attorney is called the Principal. The Power of Attorney gives legal authority to another person (called an Agent or Attorney-in-Fact) to make property, financial and other legal decisions for the Principal. The word "attorney" here means anyone authorized to act on another's behalf. It's not restricted to lawyers. See similar questions...