Models with more than one expression

[ElmerFuddFan]

He's rigged but the bones don't seem to be parented properly, all the bones are just listed under the root.
As for the geometry, you can just join the meshes and then merge duplicate vertices (Whether you should merge duplicates depends on what you want to do with it, you can see at the end the normals were destroyed by the merge).
https://youtu.be/HoXAvnOJySo

This is blender right? Can you do like a written tutorial?
Edit: I had someone seperate the expressions, hense the title, so there's 3 different models. I want just one.