#9. Optional? To make it easy, remove the ducting above and behind the wiring channel. 7mm Socket & Philips Screwdriver. It’s the same one that you remove to replace the 318ti cabin filters. You can see the dirty filters hidden back there. Now would have been a good time to have had new ones ready..... Idiot! I don’t really know if this is necessary for 318i, 318is, or 318ic people. It may not even be necessary for the 318ti, but I thought it would make things easier to pull the valve cover away.