what line are you refering too? i thought in order to do the transmission pan, you just have to make sure you have the Jeep jacked up high enough (if you don't have a lift) in order for the dip stick to clear?
The trani pan is very close to the TC x member. You have to remove the two trani / tc mount bolts and jack it up in order for the pan to clear the x member. If you don't there is a very good chance you will brake one or both of the two rear solenoids with the pan. I learned the hard way but was able to fix them. Good luck. PS. That was just two days ago
Yes, I just did that job on a 99 XJ and after fiddling around for a couple of hours trying to disconnect the dipstick tube at the joint, gave in and used a tubing cutter. Even with the dipstick tube on the bench, I couldn't pull it apart at the factory joint.
Cutting it and using a piece of hose with two clamps is the way to go.
You dont need to cut the tube. get a small hose clamp and put it on the lower portion of the tube, then hit it with a hammer and punch to drive it off. I had one on a used trans that was rusted and this worked good. I sprayed some deep creep on it first.