the rear one's are a straight swap as far as i know.
The front ones are more interesting.
1) Jack up the car and put stands under the axle's
2) Remove wheel
3) Open Bonnet and undo the nuts holding the strut in place
4) Undo the lower two bolts and move the brakes out of the way to be able to remove the strut
5) Put springs clamps on and tighten
6) using a 14mm swan neck spanner and a set of malek grips undo the nut on the top of the strut. After the nut is off remove the cup, bump stop and spring.
7) Using a power drill, drill a hole into the base of the strut (in the middle) and then pour the oil into a bucket. (Tip : drill a hole into the top of the strut to help the air enter the strut, this should be done as high as possible.
8) Get a hacksaw or a angle grinder and proceed to cut the top of the strut off so you can get the piston out. Try and do this just around were the strut straightens out at the top (roughly 5-6mm from the lip)
9) It's now a case of using a metal file to smooth the internal edge so you can put the Koni insert in.
10) While the Koni is in the strut, turn it upside down and check to see how much more you need to cut off to make the Koni nearly touch the bottom of the strut. Will need roughly another inch cutting out.
11) After you have cut the strut to the right length, its time to make the hole in the bottom of the strut big enough to take the screw. In the end i filed the hole to the right size.
12) Give the strut a quick clean and the put the Koni back in. Follow the bit of paper that comes with the koni's. It goes screw, metal ring, washer, strut and finally Koni inside the strut.
13) The black rubber thing goes around the top of the strut to stop dirt getting inside#
14) The white ring loop's just goes on the top of the Koni.
15) Follow instructions 6 to 1 to put the back on the car.
Mike