No really tools are needed apart from a small paintbrush and a Hoover with a crevice tool..
The Replacement Interval of the filter varies obviously with the environment the car is used then again a quick hover regularly can eek a bit more life out of the filter as OEM replacement is £18ish
First you need to Locate the Filter its hidden behind the trim in the passenger side foot well (UK)
to gain access you first need to remove the trim
put your fingers under the trim near the false vent and pull away

once released along this edge pull the trim towards the back of the car
as the front edge is held in place by a hook which locks into the side of the heater control unit until it comes free

next look for the filter cover

this needs to be unclipped (some might have a retaining screw air con?? but my active didnt?
)

Once the cover is removed remove the old filter (if fitted in the first place) then use a small artists paint brush and a Hoover to remove any debris

next insert the new filter (i gave mine a light squirt or AutoGlym Auto fresh on the inside of the filter element)
(airflow indiator on the filter needs to point into the car /towards the back of the car)


This is a bit of a pain to get in you need to push the top edge then the bottom bit by bit working alternately

once fully home you need to refit the cover (this has a wrong and a right way)
this is the bottom edge

you need to hook the top on first after pushing the filter slightly further in with one hand whilst locating the top catch (as it expands tight against the cover to make an air tight seal)
next hinge the cover down and clip the lower on (refit the screw if fitted)
next refit the trim by hooking the front hook onto the side of the air box
then reclip the rear section back in place
And thats it
ONE LAST THING
remember the heater matrix pipes will be HOT if the car has been used just before fitting it made me jump
Hope this helps
just to add just replaced it again and got an after market FRAM branded filter
Part#CF10282 cost just shy of £5 from local indipendent factors
The Replacement Interval of the filter varies obviously with the environment the car is used then again a quick hover regularly can eek a bit more life out of the filter as OEM replacement is £18ish
First you need to Locate the Filter its hidden behind the trim in the passenger side foot well (UK)
to gain access you first need to remove the trim
put your fingers under the trim near the false vent and pull away

once released along this edge pull the trim towards the back of the car
as the front edge is held in place by a hook which locks into the side of the heater control unit until it comes free

next look for the filter cover

this needs to be unclipped (some might have a retaining screw air con?? but my active didnt?

Once the cover is removed remove the old filter (if fitted in the first place) then use a small artists paint brush and a Hoover to remove any debris

next insert the new filter (i gave mine a light squirt or AutoGlym Auto fresh on the inside of the filter element)
(airflow indiator on the filter needs to point into the car /towards the back of the car)


This is a bit of a pain to get in you need to push the top edge then the bottom bit by bit working alternately

once fully home you need to refit the cover (this has a wrong and a right way)
this is the bottom edge

you need to hook the top on first after pushing the filter slightly further in with one hand whilst locating the top catch (as it expands tight against the cover to make an air tight seal)
next hinge the cover down and clip the lower on (refit the screw if fitted)
next refit the trim by hooking the front hook onto the side of the air box
then reclip the rear section back in place
And thats it
ONE LAST THING
remember the heater matrix pipes will be HOT if the car has been used just before fitting it made me jump
Hope this helps
just to add just replaced it again and got an after market FRAM branded filter
Part#CF10282 cost just shy of £5 from local indipendent factors