It's not hard at all, the main tool you need is a floor jack and jack stands.
Jack up the rear of the car and support the car under the torque boxes. With the floor jack under the differential, unbolt the rear shocks.
Once the shocks are undone, lower the axle and remove the springs. I have found that if you leave the wheels on, you can slip your foot into the wheel and step down, which will relax the spring on the side you're stepping on, and they almost literally fall out. Do the same thing on the other side.
When replacing the arms, remove ONE ARM AT A TIME! make sure you replace that arm before moving on. this prevents the axle from shifting around uncontrollably.
Once all of the arms are installed, do not tighten all of the bolts completely. You'll want to raise the axle back up under the body so it's near ride height. THEN tighten all the bolts.
lower the axle back down and re-install the springs the same way you took them out.
jack the axle back up and bolt your shocks back in.