[Saudade]

If I recall correctly on my '88 (4.0l, auto), the tube slips into a short extension from the pan and is sealed with an o-ring. Just pull gently and twist/wiggle the pan back and forth. Make sure the pan is as empty as it can be. It should slip off. Make sure you align the tube when you reinstall the pan.

If you follow the tube up from the pan, you'll feel the where the joint is. It's only a few inches.