Separate window lifter from disk

Happiness up!


I started to expand a rear window lifter on my 90s model today.

My problem now is that the guide rail of the lifter hangs with a pin in the plastic guide of the disc.
I assume that this pen is secured from the back (not from the inside of the door, but from the outside) with a blast ring.

I'm sure I'm not because I can't see anything, but I can only feel it.

Stupidly, I've already dismantled the engine, which, given the construction, means that the rope roll has been opened and wound - so the window is loosely moving up and down. Secured from below, but not an eternal state.

So my question:

1. I feel that right, is the thorn/bippus only secured with a blast ring?
2. How do I get this out from time to time?


Thank you and with kind greetings,

Kay-Uwe