So, a bit of a rundown on how I got the steering shaft out to straighten it.
Edit:
Before you start undoing any bolts, hit them with some WD40. These are old tractors, and the bolts are likely to snap if you try to undo them dry. Experience talking here.
First thing to do is get a puller onto the steering wheel and take it off, followed by the cowling around the gear select levers. That didn't reveal much of the steering box, so I took the dash off and the orange panel underneath the steering column. To get the two panels out, I had to disconnect the compression lifter cable, the speedo cable, the fuel sender connectors, unplug the two connectors on the left side of the tank and disconnect a wire running from the glowplug indicator to the starter switch.
It became apparent that I would have to at the very least lift the fuel tank up to get access to the two bolts on the steering box closest to the firewall. There is only around an inch of clearance between the tank and the heads of the bolts, and the tank has to move to get them out. The other problem was that the tank was full of fuel, and therefore heavy. I would have to drain the tank.
The left and right side covers are in the way of both the 8 bolts holding the tank in, and the hose from the tank to the inlet of the fuel filter.
These are a beast to try to get off, but they have to be moved out of the way.
After much undoing, swearing and re-doing up bolts, I figured out the best way to move the side covers. There are 2 bolts on each side that hold the side covers to the firewall,
Just the top two on each side, though. The bottom bolt on each side holds the firewall to the chassis and doesn't need to be taken out.
... also four bolts that hold the side covers to the frame at the front of the tractor.
Take one bolt out of each side and loosen the other one. I'd leave the forward bolt in. You will also have to take the throttle lever off to get the right side cover to move far enough to get access to the right side tank bolts and the fuel hose.
Once the 6 bolts are out and the throttle lever is off, you should be able to move the side covers far enough to the sides to get access to the tank bolts, and lift the right side cover up to get access to the fuel hose.
Once the fuel is drained and the tank is out, the steering box can be removed. Undo the 4 bolts holding it to the transmission case and disconnect the ball joint on the end of the pitman arm. You may be able to take the pitman arm off with a puller, but I couldn't get it to budge. The steering box and column can be removed by lifting it up and twisting the whole thing forwards so that he pitman arm comes out through the left side tank mount.
Installation is the reverse procedure.