Get down into the drivers footwell remove the panel at the steering column,3 clips 1 torx screw look at the heater box assembly at the centre console and remove the white air vent section then remove the small black flap,the filter is behind the flap in 2 parts pull on the tabs to remove them,you will need to bend the new filters round the column to fit them.this is a diddly job but worth doing if you want your air con to work properly.
Bodger, July 2013