Using two or more separate UV maps and textures on the same material and model I joined two meshes together and now need to add a texture to them. The entire unwrapped mesh is currently on the head's texture: (right)


You can make out the body's unwrapped mesh above the head's unwrapped mesh. I would like to move the body's unwrapped mesh away from the head's onto another texture. 

How do I separate the head's and body's unwrapped meshes onto separate textures, all in the same material? (If they can be disconnected onto seperate textures, but with two materials as well, I'm fine with that but prefer the same material).

EDIT:
To be more clear, I basically want to keep the current unwrap (yes, overlapping) and move the top unwrap (the body's) onto a different texture and keep the heads unwrap on this current texture without interference from the body's unwrap.
First you will have to unfold your entire mesh and separate one area for the head and one for the body. There can be no overlapping meshes.

Now save the 'UV layout' to do the texturing.

What I did was like that, half I used for the head, and half for the body. The rest is transparent not to overwrite one image in the other at the time of placing in the blender.
Head

Body

Now just put them in the blender and that's it.