With the release version of Vroid Studio, it is no longer directly possible to extract hair and scalp geometries as simply as in beta verions.  This change was made for the sake of mobile game character developers and VR Chat avatar creators.  However, for people like me who use Vroid Studio to create anime-style hairstyles, I need to use either Blender3D or Shade3D to extract the scalp mesh.  I use the scalp and hair I create in my scenes in Poser (and Daz Studio).

Once the VRM file is imported into Blender3D (in my example shown), I need to select the Body part under the Armature hierarchy, then Select All, then perform Separate by Materials.  Going through the resultant separated parts, and by a process of elimination (switching visibility on and off), I can find the scalp.  I export only that part of the geometry.  Done.  

It is easy to export the hair as well, because it comes in as a separate geometry provided you ticked that option when exporting the VRM from Vroid Studio v1.  So I can now get both Scalp and Hair.

I have also posted this information to my personal website here

Eternal Hobbyist