It's not really all that hard to do. Here's a good write-up on the how-to:
Steering Box Replacement - 1
I replaced mine the other day. Key thing you will need that is not part of the toolbox is a pitman arm puller. (many auto parts stores will have a free rental (you "buy" it on a CC, but get refunded 100% when you return it) or you can just buy one. They aren't real expensive, but you will need the right size (larger one) that has clearance between the jaws for the size of the steering shaft coming out of the box.
You may also want flare wrenchs for the PS fittings, depending on how tight they are.
My pitman arm came off very easily, probably due to the lubricating properties of the PS fluid that had been dripping out of the shaft and onto the arm for some time
As the article mentions, it's just thise three bolts, plus the one bolt that clamps the shaft from the steering wheel onto the steering box.
The one thing I had an issue with was making sure that the coupler from the steering wheel shaft is pushed all the way onto the splined stub shaft from the steering box. If you look at the steering box, there is a radiused recess on the stub shaft. The bolt that clamps the coupler goes "through" that recess, and if the coupler isn't positioned so that the hole aligns with the recess the bolt doesn't slide through all the way.
The article above mentions doing the job with a helper. That would certain;y be easier, but you can do it with just one person (I did). The box is a little hefty, so be ready for that when you get the bolts loose.
Once you get the box and steering shaft bolted on, you re-attach the PS lines and bleed the system as described in the article.
Fairly easy job you can easily do in a few hours, just taking your time.