If changeing the shock then you would undo the hub nut , remove all fixings other than the top stut then pull out the hub so its off the driveshaft then slide it down and off of the shock .. or just remove the whole lot in one go .. guide here for a non C4 ..
Guide does show another method although thats not the way i would do it .. far too close to the wing that way and a pain to get the suspension low enough .
Had a go at removing the strut at the weekend. Unfortunately i could not undo the hub nut, tried with a small impact gun and a long bar but it is too tight.
I have given up. so the car will have to be done in the garage.
I changed the front coffin arms on a friends car on Monday using the KS Tools 700.5610 splitter and it worked brilliantly, the jaw width is just right.