There are a lot of special tools. Funny thing is this job is not hard at all to do when you have them. It's tougher to R&R the diff than it is to rebuild it.

There's a tool to adjust the side bearings, a tool to press in and out the pinion races, a tool for the pinion seal install, and you'll need a small beam type in/lb torque wrench and a larger clicker or electric torque wrench. There's a also a puller for the side bearings and one for the pinion bearings, an installer for the side bearings and an installer for the pinion bearings.

You could save a lot by removing and reinstalling the diff yourself if your mechanic will do a bench job.