This will prove to be a true challenge for them. You're not going to like this, but anytime you deal with rust, I've found, it's best to pull everything you can. Doing so actually makes the job go faster than trying to work around everything and doing an incomplete job. To be fair, this is a time consuming process that involves, at a minimum, remove the following:
Shocks
Springs
Control Arms
Steering
Track Bars
Front Axle (with steering)
Rear Axle
Gas Tank and Bumpers
Rear Inner fender Liners
Then I break down the front and rear axles to the housings, leaving the center section in. For the front, the brakes, hub bearings, dust shields, axles, ball joints and knuckles get removed (with center section in). For the rear, the brake cables (at the tub parking brake bracket), entire brake assembly, and the sway bar is removed. Then I go to town with either wire wheeling, flap disking, or blasting the rust, depending on the severity. After that it's time for degreasing, Rust Reformer, primer, and paint.
For the tub I degrease everything then start the wire wheeling, flap disking, or blasting. Same goes for restoration there, i.e. the Rust Reformer, primer, and paint. With the axles and tub done I move onto the frame, you know the drill here, time, time, and more time to clean the inside and outside of the frame, removing all the rust possible. All of this is done first, before any mechanical money is spent. Reason being, if I find something I really don't like I'm only into the task for labor and can bail if needed.
If I stick it out, then the spending of money and mechanical work commences. You ever wonder how I get the results I do? Simple, lots and lots of work. The good news is once it's done, the job of keeping up get much easier. The point here is that this will test their resolve and teach them, as you've already done, the importance of attention to detail and the consequences of ignoring things that shouldn't be ignored.
As always, just the ramblings of a rust zealot and old man!