Editing a skinned mesh prefab from the asset store

Hello there,

I am kind of a noob when it comes to modelling and rigging. Upon now I went fine with ready rigged models and assets I purchased on the store. So please keep in mind that I do not know very much about those topics.

Currently I find myself having a hard time trying to edit a skinned mesh I purchased on the asset store. Let's say I just want to remove or add some vertices upon the head of a free skeleton skinned mesh model.

I had no luck using the uModeler, ProBuilder and I was unable to try it with QuickEdit since I do not find it available anymore nowhere and I guess these editor assets are simply unable to deal with skinned meshes.

I had no luck using the SkinTools asset as well but maybe I was just missing something, but found myself unable to select and manipulate vertices.

I also imported the FBX file to Blender, edited some vertices and then exported the FBX back again and loaded it in the unity editor but the result was... I cannot really tell... odd... It was just a pinkish mesh not really sharp to the eye anymore... I had no luck with this...

Just to state it clearly, I just want to edit the mesh (some vertices of it) at the moment, not the bones neither their weights nor the animation.

I also tried to look up similar topics but found no viable solution so far.

Is there a tutorial or any howto available that takes a (free) skinned mesh from the asset store and edits the mesh (atm I don't really care if through the use of an editor asset from the store or via import/export to Blender)? Where could I read about the steps to take?

Your help on this topic would be appreciated very much. Thank you.