"1/2 the fun"? You obviously have never changed the filter in a 300D with iffy engine mounts.
The filter is mounted on the left rear lower portion of the engine. That spot right there where ALL the goop from the power steering, fuel and every other fluid which can and does collect.
If you don't have a lift then support the front of the car on jack stands. Leave the key in the #1
position (ignition off, steering unlocked). You will probably need to move the wheels to allow the canister to clear the steering linkages.
Slither under the car and look directly up at the rear of the engine. You'll see a large canister with a bolt head at the bottom of it. I believe it is a 15 MM. Loosen the bolt and the canister will begin to drop. At this point you, even though you were sure you had the drain pan correctly positioned, oil will still spill on the ground. Allow the oil to drain and then remove the bolt allowing the canister to drop.
Clean the canister, receiver housing and the tools you managed to drop into the oil. You can clean the pre-filter with mineral spirits, carb cleaner, etc.
REPLACING the canister, filter and O-ring is the second part of the "fun".
Hand tighten the bolt until the o-ring is seated. Spin the canister by hand to ensure it is correctly aligned before tightening the bolt. It is easy to get the housing cocked in the receiver which you won't discover until you start the engine.