I'll assume your setup is the same as my '85 380SE, also a W126 chassis....There are 3 small bolts (8 or 10 mm, I forget), 2 located on each side, at the bottom, just inside the doorsills, and 1 at the center, under the armrest. Remove these and push up on the back to release it from the 2 hooks.

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1986 560SL
2002 Toyota Camry
1993 Lexus