Anyone familiar with older Magura HS rim brakes?

I got these old HS22 Raceline off eBay and trying to fit them to my 90’s steel mtb.

They don’t sit 90deg to the rim surface, but they point down. They are also very close to the tire and are too narrow, so the wheel is always braked. Naturally, they need to be adjusted.

I think that I need to rotate the the two light grey prongs on the fork-side of the brake, the ones that hit the fork and give the piston its stop to avoid rotating around the cantilever mount. But I can’t figure out how to do that.

The two anti-rotation prongs look interference-fitted around two pins who on turn are interference-fitted inside the rear piston holder. There is no adjustment and if I push anything out I’m afraid that I will lose interference when they’re fitted again and the safety of the brake is related to this interference, because if it gives way during braking you suddenly have no brake anymore.

Any tip or hint? All the material I can find online about HS brakes is about a newer design, there this anti-rotation is made not against the fork but against a horse-shoe looking part.

Thanks!