None of the jobs you speak of are difficult. I did the plugs on my E430 - not bad at all. The trickiest part is getting the boots loose. I hear you can use one of the old M-B valve adjusting crowfoot wrenches, but I had given mine away. I used a hook from a peg board (the board you put up on the wall and put hooks for tools on). I spread the part that fits into the peg board for a nice fit over the metal part of the boot, slipped a piece of 1/8" pipe over the hook part, and pried against the valve cover. Remove the entire coil unit from the valve cover and set aside. A spark plug socket with a 4" extension should work perfect. I removed the air cleaner housing on the pass side. Just go slow and careful.