2002 Mercedes SLK 230
I replaced my spark plugs at 50,000 miles. The procedure is a bit tricky because you first have to remove the coil assemblies, which requires a Torx Socket set (such as Car Quest STL 26750 — $17.99).
Start by removing the three hex screws on the orange “Compressor” cover. This gives you access to the spark plug coils:
Remove the wire harness from each coil by pressing down on the lever and pulling straight out:
Notice that the coils are held in by Torx bolts. You’ll need a Torx socket to remove these:
You can now just pull out the coil assembly:
The Spark Plugs can now be replaced with a standard spark plug socket and extension.
Assembly is the reverse procedure.
Updated: January 2017 Contact: Hoeren at Comcast dot net