When cool or cold the steering will lock up when.

The rack is the cause of loss of assist when cold in only one direction. You can also separate the steering linkage from under the dash. There is a 13mm nut to back off after a small cotter pin is removed. The nut will stay in place and the special bolt will back out and come off. Swivel the coupler to separate it.

It is important to understand that it is real easy to damage the clock spring under the steering wheel. That is a wound-up ribbon cable in a plastic housing. It is only long enough to wind up and unwind about 1/2 revolution more than the rack and pinion will allow. If you disconnect the steering linkage, turn the steering wheel one full revolution, then reconnect the linkage, that clock spring will be damaged as soon as you turn the steering wheel fully left or right. One way the ribbon cable will get tight and snap. The other way it will fully unwind, then fold over on itself. Eventually it will crack.

What you need to do to avoid damaging the clock spring is start with the steering wheel in a specific position and hold it there with a rubber strap to keep it from turning. I always set mine straight ahead. Install the new rack, then push on a tire to set them straight ahead, THEN reconnect the coupler. That will keep the clock spring in the same orientation, halfway between full left and full right. It is critical the steering wheel is not rotated while the steering shaft is disconnected.

Once the rack is removed you'll be able to punch the roll pin part-way out, tap the coupler off the splined shaft, and transfer it to the new rack. It won't hurt to totally remove the roll pin but if you leave it partway in, it makes it easier to reinstall it when doing that in the vehicle. There's a flat spot on the shaft so the coupler can't be installed in the wrong orientation. You may find you can't get the rack out with the coupler still on it. By separating it from inside though it might drop down enough that you can get to the roll pin easier. I took a broken long air hammer punch and turned it into a round punch just right for reaching those hard-to-reach roll pins. That made removing them easy, but if it came all the way out it was hard to reach up there and hold it in position with one hand and swing the hammer with the other end. A trick to help with that is to grind a slight taper on one end so you can wedge it in place like a nail. You'll only have to reach up there with one hand to run the hammer.

The van will need an alignment to set "toe" on both wheels when you're done.

Forgot about the lines. Use a flare-nut wrench, (line wrench) because the nuts are soft metal. They are available in crow's foot too. Be sure to start them by hand when you put them in the new rack. If you cross-thread them and wreck the threads they will not warranty a rebuilt rack for that. If the nuts do not swivel freely use some brake parts cleaner to loosen them up. If one is rusted so tight that the metal line looks like it's going to twist, spray it a few minutes before with "Rust Penetrant" from the Chrysler dealer's parts department. It's black and sizzles when you spray it on. It does in ten minutes what WD-40 will do in a weekend. PB Blaster is supposed to be good too but I've never used that myself.