It is not too tough, much easier than the a/t. The main places to look for excessive wear are the input shaft bearing. You can diagnose this in the truck. Accel to a steady state speed in 2nd or 3rd, and get on and off the gas while watching the shifter. If you see a fairly large fore and aft movement of the shifter, you have input bearing wear as the mainshaft moves fore and aft, moving the shifter forks. When it gets large enough, it pops out of gear.

Get the fsm and follow the manual, and it will be pretty easy. You won't have the special pullers for some of the stuff, but I've been able to drive it apart with blunt punches and a hammmer. Parts are available.