mmmhh… the reason, why you will (in my opinion) never, ever find a tutorial, which explains “your way” is, that it is nearby impossible to “redesign” a given head-face topo. Some scupting-gurus, I mean really highly expierenced ones could do something like this, but they won’t ever. Cause in reality it’s much, much easier to set up a new head from scratch.
Imagine something not-virtual Let’s take a head formed by clay. Let’s say it’s a very good work which shows Christina Aguilera. And now you want to change this one into, let’s say the face of John Claude van Damme…
??? Do You think that’ll be easy? Hope you get what I want to tell you.
As for a beginner, start up with the basics of modelling. get a feeling what it means to “build” a mesh. Get the rules of topology on easy meshes. And then go into learning character modelling. Again, get the rules of topology on this type of mesh and then, maybe then, you will be able to cut off the head from a given model, create your own one and “connect” it to the original body-mesh.
That’s only an advise, from someone who started some years ago with the same “dream” of getting something created like you try today. I failed and I nearby gave up. But then I started to learn from scratch and now, slowly now after some years now, I feel ready to start realyzing my initial dream.