I'm just going to be able to give you some generalities on this one as I haven't seen one of these personally, but have torn apart a bunch of similar cars over the years.

Ford used a couple of different types of boxes. One had a rag joint at the bottom in front of the firewall, and you unbolted either the rag joint by removing a couple of bolts that go right through the rag joint itself, or you can take out the one bolt that pinches the joint to the steering shaft and pull it away from the spined ends.

The second box used no rag joint , but instead the steering shaft from the wheel to the box was one piece and was a part of the box. When this one was out of the car the box had about a 3-4 foot piece of the shaft as part of it. Sounds to me like that is what you have.

If so, first remove the steering wheel, and I think you will find a round clip that fits into a groove cut into the steering shaft. It is usually right up against the top of the outer steering column tube. If that is there a very small screwdriver will pop it out of the groove. Then you can either put the car up high enough so you can slide the box and attached shaft out of the outer tube and under the car. You can also unbolt the entire outer tube, get it out of the way, then work the box and shaft down out of the car.

I can't swear 100% this info is correct, but it should get you close enough to figure out how to get it out.

Don