if you plan to change the whole axel because a boot or joint is bad, i would suggest you just repair the piece needed. aftermarket axels are often rebuilt "junk" that cause more problems then they solve. as far as how hard, depends on your talent and how siezed some bolts can be. the only odd tools that you will need are a 17mm allen socket for the main axel bolt and a #10 spline socket (maybe #8 i forget) for the axel to trans bolts. to make enough clearance to remove the axel you will need to either pop out the upper control arms by removing the pinch bolt (which usually siezes) or unbolt the lower guide link (big curved arm). if you loosen any bolts in rubber bushings be sure to tighten them with the car not raised. before ever jacking your car remember to turn off the air suspension (service mode).