...is an absolute doddle! 5mins from start to finish. I was expecitng about an hours worth of fiddly work and loss of much skin on my hands, but ity turns out for a RHD car it's a piece of piss. Drop the panel below the steering column (4 screws) and remove. you can then actually see the 'locking piece' on the cover of the HVAC box at the back alongside the pedals. (it's got 2 pegs on the end of it). Rotate 90deg anticlockwise and remove. Slide out old microfilter. Crack the new filter element carefully along the 2 moulded-in weak lines and insert. Even this is not too fiddly. Pull tab on microfilter towards rear of car to seat the filter element. Refit cover and you're done. Thanks God we have the steering wheel on the *right* side of the car.
JB