October 28, 2010, 2:44 am
Heres how you do it. (taken from another website
1) Filter is located in a vertical orientation at the very back of the heating and ventilation unit.
2) Filter cover is fitted using 3 or 4 off 7mm hex screws (mine had 3 fitted).
3) Access is from passenger foot well.
4) Remove side panel attached by 2 off T25 screws behind covers.
5) Remove the 2 off 13mm nuts that fix the main fuse board bracket; this allows you to drop the main fuse board down out of the way.
6) If you have a Ghia there is an air-con pipe for the cooled glove box. This is in the way and cannot be removed from the heating and ventilation unit. However it can be disconnected at the glove box end (simple push fit).
7) You can now remove the pollen filter cover screws and remove and replace the filter. You may have to flex the filter to get it in as you can't get straight access to it.
[url="http://www.focusowners.com/forum/viewtopic.php?f=117&t=47908"]http://www.focusowners.com/forum/viewtopic.php?f=117&t=47908[/url] That should help.