[Yosemite Sam]

It may be possible to remove the speed control rod with the assembly still in the tractor, I don't know, I've never done it that way.

From your picture it appears that the outer tube from the steering column has been removed. If that's the case, I would remove the dash tower and give yourself some space to work and a better line of sight.

It is possible to get a wrench (1-1/16" or 1-1/8" I believe) onto the nut (#21) unscrew the nut, and the rest of the pieces above the support should slide up on the rod. There is a dowel pin that does through the rod and (I believe) the friction adjustment shaft. Removing the dowel pin will free the rod from the rest of the assembly. IIRC the friction collar is slid down over the dowel and most of the friction adjustment shaft preventing the pin from falling out during use.

It may also be possible to remove the ball joint, then the nut and at that time, the rod and friction shaft may fall out the bottom. Sorry, it's been awhile.

Note: It is entirely possible that in order to unscrew the nut, the wrench must go onto the nut and then the parts must be turned while holding the nut still, the wrench removed, the parts turned back, the wrench put back on, parts turned, wrench removed, parts turned back... Until the nut can be turned by hand. Please understand that this is from memory and it's been a long time since I've done this.

If there is much rust on the dowel and connecting parts, removing the dowel will prove to be difficult at best while still in the tractor, especially if the tower is still in place.

Still, I think the easiest is to remove the assembly, make the repairs and then put the assembly back in.

Good Luck