I just changed the plugs on my '08 M3. I read all the blogs, and was worried about pulling the coils. When I removed the cover over the colis I saw that there is a "button" on the top of the coils that is 1 inch in dia, with a stem of 5/8". I McGivered a puller by sawing a 5/8" slot in a pipe hanger. It worked beautifully. The hole of the pipe fits my finger perfectly and it is rounded over for painless coil extraction. For the rear coils I used a pry bar in the hole with a block for a fulcrum. See photo. The string makes it easy to retrieve the puller when you drop it, as you inevitably will. If anything falls onto the engine pan the gremlins eat it and it is never seen again.
The entire job took about 2 hours, including time to buff and clean the parts.
