I've described it a few times in this thread already I believe, but it's quite simple once you get access.
No need to remove the wheel, but you do need to jack the car up and remove three clips to release the arch liner. You'll be able to see the top hat, and also the gap above it where you need to get your fingers in and remove the rubber dust cap before adjusting. Remember to turn it fully clockwise (firmest setting) before counting the clicks turning anti-clockwise.
