I would like to replace my '89 420SEL's spark plugs. (I figured that step-by-step instructions for doing so would be located here, on ShopForum, but searches keep coming up empty.)

Would someone please help me (and others) by either providing a straightforward set of DIY instructions for this job OR by directing me to an existing thread containing the same?

Thanks as always!

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Eric

1991 560SEL-Euro (214,000 miles)
1989 420SEL (Retired from daily use at 325,000 miles; Use as donor vehicle)