fairly easy if you take your time.
fitted mine yesterday, and it makes a MASSIVE difference to the feel of the car.
few pointers:
1) unclip the brake pipes wherever you can, on the passenger side do it to the front of the car, on drivers side clip it off the trailing arm and around the fuel filter.
2) use a drill with a fairly large sharp piece, i made two holes right at the bottom edge and with a tap with a hammer and screw driver it fell right out, much to my suprise.
3) you'l just need a standard socket set, and some guns.
4) grease the CRAP out of the powerflex ones, easy getting them in the trailing arm, but getting the mount that attatches to the car over them is tricky, and hard to align the holes, get a hand with that!
thats pretty much it. oh, and you'l need alignment afterwards. The mount to the car has elongated holes, so there is side to side adjustment (for toe in/out). just try and put it back as it came off, there will be marks left by the bolts.
hope thats clear