Haven't done it myself, but the connection on the steering box uses a roll rin. You will have to drive that pin out, and that can damage the seal around the input shaft to the steering box.
If you can brace behind that shaft somehow so your hammer blows don't go 100% against that shaft, you have a good chance of not damaging the seal.
There are lots of ways to accomplish that, you'll have be creative to make something/wedge something in there.
Hope this helps.
Jay
edit... Use loctite on the bolt/nut threads. Important.