I just did mine the other day, the pump faces the wheelarch liner, its fairly simple to get to, but make sure you have some of those black plastic clips spare before you start because its nigh on impossible to remove them without breaking them.
wheel off, couple of torx screws, one is vertical under the bottom of the bumper, i removed two of the black clips, just push the centre in then it will remove, getting the centre back is the hard part.
There was untold ammounts of gunge on my filter, toothbrushed most of it off then had to use a pin to clear the rest.