Ask the principal which counties the power of attorney was filed in. Make a list of all the counties. If the principal is uncertain, include all counties he may have conducted business in.
Prepare an original revocation form for each county you must file in. Use the original revocation form as a guide. Have the principal sign and date the revocation forms and get her signature notarized. Notify the agent of the revocation. Get all copies he may have of the Power of Attorney.
Bring the revocation to each county office that maintains the land records, typically, either the county clerk or county recorder's office. Ask the clerk to look up the filed power of attorney and provide you with the instrument number that identifies the document in the record keeping system. Write the number on the revocation and file it. A fee may apply, but it varies by state and county. Ask for a certified copy. Repeat the same steps for each county on your list.