for this, a revocable living trust or last will and testament will need to be created before the death of the individual. included in the advance directive is a medical power of attorney form which allows the principal (the estate owner) to nominate a health care representative. the principal can use the advance directive to outline their end-of-life medical preferences and choose their official health care representative. durable (financial) power of attorney – allows the principal to appoint an attorney-in-fact and assign them with powers to handle their finances.