However, you'll need to be precise:
* Access: You'll need to get underneath the car using jack stands (never work under a car supported only by a jack).
* Identification: The pan itself might be somewhat difficult to distinguish from other components. Look for a relatively large, rectangular or slightly curved pan, likely made of steel. The drain plug is usually a bolt or similar fastener on the lower edge of this pan.
* Caution: Transmission fluid is hot when the engine has been running. Allow the transmission to cool completely before attempting this procedure. Also, be prepared for a mess; have a drain pan ready to catch the fluid.
Because of the potential difficulty in locating the exact plug and the risks involved in working under a vehicle, I strongly recommend consulting a repair manual specific to your 1986 Cadillac Eldorado. These manuals will have detailed diagrams and instructions to help you safely locate and drain the transmission fluid. A Haynes or Chilton manual would be a good starting point.
Disclaimer: This information is for guidance only. Improper maintenance can damage your vehicle. If you're not comfortable performing this task, take your car to a qualified mechanic.
