How to get rid of this overhang?  

RE: How to get rid of this overhang?

Assuming you are printing with a standard profile then that's just the result of the cooling not doing a great job on the overhangs.  Default profiles generally use max cooling on those so its about as good as you will get unless you modify your hardware for better cooling.

Without you saving your active project and zipping it up so we can see your settings then we cant really tell if setting changes would make any difference.  

You could post process the overhang, ie file/sand it.
You could add supports.  Although I think that would be pointless as you would still  need to post process the surface anyway in all likelihood.

You could also alter the model to remove/reduce the overhang by changing the geometry too.  I have attached a modified version as an example.

RE: How to get rid of this overhang?

Many Thanks for your fast reply, I am using standard settings as I am overstrained as a noob and do not often understand the explanations Prusa Slicer or Knowledgebase is givin me. I will try it with your version and let you know, but many thanks again for your input and support.