On my 1984 300SD the emblems are held on by three little studs on the backside of each. These studs have a press fit into nylon grommets that are pressed into the decklid sheetmetal. I used a plastic shim (used for squaring door frames in construction; available at Home Depot, etc.) to carefully pry the emblems off. The little grommets are commonly replaced when repainting since they're often buggered up. The dealer parts dept. should know them well, and it may help to get some first to see how they work and their size. (~$.75 ea)

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The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)