from what i have done the hardest part to me was setting back lash making sure the gears grab just right. the only special tools i used was a slid hammer, pully puller for the drive shaft flang, and a press to put the new bearings on the pinion gear and the carrier. its not to hard but you need to take your time on this you dont want to get dirt in there at all but you know that part already.
sorry i thought i posted this already i just used colored grease to set the gears. put some grease on the ring gear spun the gears a few times to see the contact path. it was a trial an error things but it was just one shim shy of what we wanted. so it was a good all an all i would do it again.