Right then, first off do you have some spring compressors, as if not then you need to take the struts to a garage as the new one might not need compressing but the old ones will.
Step 1 - undo hub nut first before removing wheels, on mine they are 30mm, but they will be either 30 or 32mm.
Step 2 - jack vehicle up and remove wheels, use axle stands.
Step 3 - undo bottom ball joints, on mine they are 16mm, leave the nut on a few threads and knock the bolt out, so you don`t damage the threads as they are special bolts.
Step 4 - i use a hammer to knock the wishbone to release the ball joint, or if you have a ball joint splitter than use that.
Step 5 - undo the steering rod, again it should be a 16mm and leave the nut on a few threads and hit the strut rather than the rod end to release it.
Step 6 - once the above are complete, get someone to support the strut while you undo the 3 13mm nuts holding the strut to the body, or use a jack to support the weight if you are on your own.
Step 7 - the strut should now be on the floor, now is the time when you need the compressors. I usually mark the strut top to the strut so it goes back on the same way round, scratch the surface so it doesn`t rub off ( i used to use chalk, but not anymore )
Step 8 - Compress the spring and use a air gun to undo the centre nut, i usually leave the weight of the spring a bit so it doesn`t turn the shock, but only a bit of weight or it will shoot the strut top off when the nut is off.
That is basically it, locate the new spring in the cut out on the strut and reassemble it again.