Removal of rear seat backrest

Guys,

I`m currently trying desparately to remove the rear seat backrest of my wagon to be able to remove the rear trim what covers the area between seat and rear wheel. It looks like the pivot point of the backrest goes through the trim of the wheel arch, , to get it out the backrest has to be removed to my opinion.
I don´t find any carrier or something what seems to be part of the pivot point , are there any bolts with access from underneath the car? I even tried to find, but I didn´t. No idea how to get the pivot points or the backrest out.

The reason to do it is to replace the wheather seal of the doorway, the seal is fixed with the trim what has to be removed.
Thanks for any help

The panels do not have to be fully removed to change the rear door weather strip. Just have to pry them loose from the opening and then pull the clip from the panel. It will then come out with the weather strip. Put clips on replacement strip and put it back in.