A specific question, but maybe someone here knows! My shower has a drain. When I remove the cover and the “thing” inside of it, there’s a stopper with an O-Ring.

We used to be able to pull the stopper out and clean inside the pipe (suggested by a plumber), but I now can’t remove the stopper anymore. It appears to be quite stuck, and the angle is also terrible to get a better grip on it. I don’t want to use pliers, because I’m afraid I might snap the thing that you hold, and then I’m really in trouble.

Can anyone give me suggestions what I can do to get the stopper out? Is there a technique I don’t know? A device I could buy?

Thank you!