Passat Variant: Exploded Diagram of Seat Back Lock

Hello there.

I am urgently looking for a diagram or explanation of the locking mechanism for the backrest in a Passat.
variant 3bg. Unfortunately, the AKTE representation is not detailed enough.
background: I tried to adjust the backrests. Unfortunately, without exerting any force, I held the operating parts in my hands, and there were no springs or anything else visible! It seems that the previous owner may have tampered with something!