The latch from our front door detached itself from the door knob and, in pure mustachian fashion, I'm trying to put it back myself before calling a locksmith. In order to do that, I have to remove the door knobs, put the latch back, then put the knobs back. Problem is that these door knobs look a bit complicated (I'm a tenant in the building, I assume they use these commercial-grade knobs intentionally).
I managed to remove a few things, but am blocked at what appears to be the last step. The video here [
https://www.youtube.com/watch?v=qU1BwoMOFyk ] shows a door knob similar to mine, and mentions a retaining ring that needs to be removed. I see the retaining rings (pictures below), but they don't move, no matter how hard I try (I tried using two screwdrivers, pliers,...). It almost looks like I'd need a very specialized tool, some sort of cylinder of the right size, to remove these things. Am I screwed (pun not intended)? Should I call a professional locksmith? Any suggestion welcome
