Need Advise on Replacing Spark Plugs and Fuel Filter

I changed the plugs and fuel filter on my wife's 2000 E320 before the 60K mark but at the 4 year make while still under Starmark. I used Bosch F8 DPP332 platinum plugs and a Bosch fuel filter. The filter was located under the driver side rear seat. A cover is removed by removing about four plastic nuts. Before removing the fuel filter you need to remove the gas gap to help depresurize the system. You may need to get some small hoze clamps since the existing clamps broke off during removal due to the use of a special tool to put them on. To replace the plugs allow the engine to cool down, remove the air intake and the plastic cover on top of the motor by lifting up on it at each corner(it will snap off in 4 places). Removing the wires is difficult due to them being on for so long. Using an 15 or 17mm opened end wrench with offset end wedged on the valve cover will help. The most difficult to access is the driver side rear. Removing the coils on top of the valve cover eases access. It is best to replace each wire in its original position (they are not all the same). Use a plug socket with a rubber retainer to hold each plug and attache a short extension. You need a torque wrench to properly tighten the new plugs. You will save and learn alot. Keep your old plugs for future inspection (they will help diagnose potential problems by cylinder). Allow a couple hours if this is your first time.