Looking at the service manual, looks like a very easy job to do.
There is an oval shaped plate (#20) bolted to the rear end housing with two bolts (#21). Pulling this plate out, will expose the seal (#19). You can use two self tapping screws and screw them on the seal so you then have something to grab onto with pliers and pull the seal out.
Keep in mind that if you don't drain the system, you'll have a bunch of fluid coming out. You can also jack up the rear end to avoid draining the system.