Facing the car the air box is to the left. Undo four clips, remove element, clean out the air box, install new element (read the arrows for the direction of the air flow), reattach clips.
How do I change the oil filter on an Audi A4 Diesel 2007
4 clips, unclip all four and pull element out.
audidiy.com
behind the glove box
Over by the air filter's box.
beetween the trhotle and air filter housing
Fuel flter, air filter, spark plugs.
Need to change oil and filter on an AUDI 2012 1.8T, how many quarts of oil do I need
is your a4 diesel ?
All garages in Leicestershire should be able to do that.
Open the hood of your Audi. To the left side you'll see the engine intake filter. Just above that and behind is the cabin air filter. It's easier to see if you remove the engine intake filer.
Open the hood, look toward your left, and go to the firewall. There is a black box, this is where it lives.