from the toolbox, select the CloneStamp tool.
Press ALT and select the portion of the skin of the face just near the moustache. (but not too near)
Release ALT button and now click on moustache. the moustache will take the color of the skin. Do this on the whole moustache.
With little practice and grip, u will be able to do it.
@Goobi , the thread is still there in Tutorial section.