You can change textures easily with MDBCloner. As regards the texture itself (or more precisely how it is wrapped on the model), it's sometimes not easy to figure what shape is for what part of the model!
To make a skin tintable, it's very easy in the principle: just put red, green and blue colors where you want tint1, tint2 and tint3 to apply (not necessarily in that order though, I don't remember which color goes with which tint). How to do it is trickier, as you need to know how the texture is unwrapped. By the way, color blends work too (a white part will be colored by the three tint colors, a purple patch will only be affected by tint1 and tint3 (following the RGB and tint1, tint2, tint3 order I chose above).
Then, with MDBCloner, add the texture to the tint textbox and you're done (for testing purposes, you may work with the diffuse texture [i.e. the dark one you see]) and make it whiter (save as a different name of course). That way, your model will look more albino, but then you can easily change the skin color.
Hope this is clear enough!