Who told you it had one? It doesn't. You can drop the whole pan but that will get you only about 20% of the total fluid capacity.
The only way to get it all out is to use a fluid exchanger machine, often called a transmission flush machine. It ulilized the cars own pump to replace all of the fluid. A little further advice is, if that car has 100k or more and hasn't already been changed on a regular basis, you cause more problems than you will fix by doing that.
Edited by Tech501 on April 10 2005 at 9:05 PM