So, with a bottle of Meguiars Interior cleaner and half a dozen microfiber cloths surrendered to the cleaning gods, it was time to start the actual fitting.
With the boot/trunk being the last area I tackled on the breaker, it was there I started the refit as it was most fresh in my mind. It takes time, but is really logical to do. If you take out the left panel which hides the toolkit and CD changer, you then see a couple of push-fit fasteners. When they're taken out, another bit of trim is freed up. That in turn exposes a couple of screw heads, which, when removed, really start to strip the panels away.
It's like big, expensive Lego really, and is both pleasing and methodical to work on, even for a complete novice like me. Here are some pics of the boot stripped and refitted, with the rear seat in place too:
