So they are not held on with a circular clamp / or screw as per a CLS i once owned?
I took mine off to get them re-chromed, but it turned out they were made from Stainless Steel.
The guy at the plating company charged me a £10 to have them re-polished professionally.
Fine grade wire wool or even 3000 grade emery paper with Autosolvosol, then same again but with a good microfibre cloth, plus the usual hours of elbow grease.