it is not too bad, it is heavy and very dirty work. You may have a hard time removing the steering gear from the pinion shaft on the steering box, you may need a special puller to do that if your new steering box comes with out one. make sure to mark all your parts and put them exactly back the way they came. Also, count the turns on the steering box so it is centered enough to get your truck to the alignment shop which is mandatory after a new box is installed. Check all the steering box mounting bolts, be sure none of them are cracked, this is not uncommon. Best of Luck and be really, really safe!!
here is site with repair info for your vehicle http://bit.ly/alldata_repair_manuals