Removing rocker panel trims / covers
 

How difficult / easy is this on a W124 and a W126?

I have some rust on both in that area. Not too surprised on the W126, but I thought that W124's didn't rust... :(

They are held on with pressure clips that typically break when you remove them. Typical removal is to slide the panel towards the rear, then lift from the body.

As a little "factoid" in addition to being called "cladding" or "protection panels" they are also nicknamed "Sacco Panels" in honor of their designer.