I've swapped the passenger side out, pain in the a%$e! To get both off you basically have to dismantle the rear end of your car.
You'll need to remove rear bumper, side skirts, boot lid, lights, parcel shelf, undo many roof bolts and peel the roof forward. Then you may start undoing the target wheel arches. While most of it is just time + spanner, there is some panel lining up to do and putting the boot back on can be nice and tricky.