It depends on how much of it he removed. If he pulled the entire thing (steering column, box, pump, brackets, etc.) look at spending about 4-5 hours if you have never done it before or are not quite "mechanically" inclined. If you have any mechanical skills, it is actually a very easy job to do. I blew the seals on the PS box on mine and I pulled the box, replaced the seals & reset the box in less than 2 hours. So, if you have confidence in your abilities, do it yourself, it shouldn't take more than a couple (2-5) hours, like I said, depending on your skill level. In terms of comparison, if you can re-pack the bearings on your front hubs, you shouldn't have any problem doing this.
The one thing to make sure of though is that everything is there and that the steering linkage is for the 77 and not the 72. They are two completely different steering set ups and if he swapped the linkages, make sure he puts them all back. The 77 is what is called an "inverted Y" linkage and the 72 has "T" linkage.
