I have no direct experience with the S-Class lower body cladding, but I suspect that the design is similar to the E-Class cladding. The chrome trim strip is held on by clips accessed from the back of the cladding panel. Therefore, first you must remove the cladding from the door. There should be a philips head screw at the lower edge of the door that secures the panel. Remove the screw, carefully pry the bottom of the panel away from the door to release the series of clips holding the lower edge in place. Once all the bottom clips are free, carefully slide the panel toward the rear of the car to release the top clips from their slots. When the cladding panel is removed you'll see the series of clips that hold the chrome strip in place. Turn them 90 degrees to release the chrome strip. I doubt that you'll be able to straighten it ... better to buy a new one at the dealer or one from a salvage yard. It's also very likely that you'll need to purchase many/all of the 3 different types of clips as they become brittle and break during disassembly.

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Fred Hoelzle