It's hard to tell from the pictures the condition of the suspension components, but they do look better than mine did! You can replace the differential bushings relatively "easily" in comparison to dropping the whole subframe. I did the diff bushings with the whole subframe off the car because it was also very clear I needed new linkage and subframe mounts, so it made sense to do it all at once. If only the diff bushings look extraordinarily bad, though, I would just do those. You do need a special tool. I know some guys have made their own, but I borrowed the proper tool and it made it rather easy (that part, at least!).
Doing the entire subframe is pretty involved, at least I felt it was ... just visit my thread for a preview:
A subframe question (just the beginning ...) 
That said, I did finish it, and the car rides amazingly now (as you can see in the thread, I'm still dealing with a slight, probably unrelated wandering issue, but the improvement is still profound). I'm going to add some photos soon if you want to see some real ugly undercarriage.
If you're
just doing the diff bushings, you support the car, remove driveshaft (three nuts/bolts), remove the ABS sensor, support the diff, remove two rear bolts, remove front nut on top of front diff mounts (that was really tough, even though I was doing it OFF the car), carefully lower diff, use tool to remove rear bushings toward front of vehicle (they're tapered so direction matters), use tool to push in new bushings from front rearward taking care to get the right "clocking," lift diff back up and slide in new front mounts (don't forget the spacer washer), replace bolts and nut, replace driveshaft and sensor.
That's not a thorough writeup at all, and I might have missed something, but I just wanted to give you an idea of what's involved. If you decide to do it, I could write something more detailed and add some pics too. I would also recommend ordering new hardware (the bolt and nut for the front and the rear bolts) in addition to the mounts. They were very rusted and the top nut stripped a lot.