not so much difficult but you need the right tools, the rears are easy enough to do, idealy 2 person job though, bit fidly just using axle stands and trolley jack, the captive nut inside the rear beam that hold the bottom of the shock can be a pig too! a good soak in wd40 the day before your gonna do it is a tip! get new bottom nut and bolts too its safer and easier, another tip on the rears is once the coilovers on its hard to get the bolt in or out on the off side rear as it fouls the fuel tank!! so you need to locate the bolt early on in the job, as for the fronts i had a mate at the dealer