I just got done doing this. Seriously, just this afternoon.
Took me about 30 minutes all together. I've done it a few times now over by years of Benzing.
Piece a cake really. Bent over the driver side fender. Use a little small 10 mm combination spanner. Be prepared for a small gush of oil to come out.

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Current fleet
2006 E320 CDI
1992 300D - 5speed manual swapped

former members
1984 300D "Blues Mobile"

1978 300CD "El Toro"