The office is located just west of Ann Arbor, easily accessible by Jackson Road, I-94, and M-14.
You may get an interactive map to the office from Bing or Google.
The office is located in the second building (see satellite photo at right), you can barely see the boulder next to the driveway off Little Lake Drive, but you will see it when you drive in.
I have put up some photos to give you a better view of how to get here, coming from the east, west, north or south, or from inside Ann Arbor.