Changing air filter on 1999 BMW 730d (Common Rail diesel) Tools required:
HEX toolset. New air filter element.
New air filter element looks like this:
This is a bosch replacement element.
To start with lets see where to start, thirst disconnect the air flow tubing on the left side of the engine (the tube I'm holding in my hand on the next picture)
Red arrows show where the air filter housing bolts are located, use HEX screwdriver to unscrew 5 bolts, they'll stay in the housing so no need to worry about loosing then.
Now remove the oil cap.
Filter housing is now free, and you can remove it.
Housing removed
Old filter element is in place.
To put a new filter element you might want to move diagnostics socket out of the way, socket is easily unclipped.
New filter in place. A note is required here, filter element must be orientated correctly.
So when everything is in place, it's time to finish it all up, screwing all the housing together.