Plastic cover on the C-pillar at the V8 - disassembly??

Moin moin,

after I have used the search function unsuccessfully, have flown over the RLF (admittedly not sooo intensely), I ask the question here:
Does anyone know if and how to get the plastic covers in the C-pillar (which directly above the transition to the trunk) at the V8? In the crack it starts to rust and so you get there only conditionally. I'm a little scared to tear it around and not buckle the mechanism until I have the part and the plastic nubsis that attach it individually in my hand... (force before technology and stuff)

Thanks for all the tips and hints on other posts, pages in RLF, etc...

Greetings to the V8 community
Roman