Where is the cabin filter located on a 2002 Ford Tarus

The Cabin Filter is not unlike the standard air filters you replace regularly. The difference is that this one is a bit thinner/smaller.
Locate the passenger side cowl. In plain english, this is the plastic piece just below where your window wipers sit when they are at rest. There are two "cowls" One on the driver side, one on the passenger side. You will be removing the passenger side only.
With the hood up, stand at the front, passenger side of your car. Face your front windshield and look for a series of small metal retaining clips at the base of the cowl (closest to the engine, not the windshield) You will remove the first three only - counting from the passenger side toward the center. One clip holds the left and right cowls where they meet

Under the hood on the passenger side. Remove 2 or 3 plastic nuts just below windshield wipers