Try duplicating the layer, and setting the layer mode to screen. If the skin is still too dark, repeat. If it is now to light, lower the opacity.
If there is still too much color, instead of duplicating the layer, add a black&white adjustment layer, and do the same thing. Add a normal layer also set to screen or a hue adjustment layer set to color to bring some color back.
I'm not sure what you are going for, but one of these methods should get you started.