Basically, you need to have two images - the "background" one you are dragging onto, and a second one which is the wig.
I would suggest that you want to handle the Paint even of a panel or similar, and that you need to look at using the
Graphics.DrawImage[
^] method and also the
Region[
^] class for setting the area you want to draw the wig into.
This isn't a trivial job at all - you may want to look and see if you can find a basic graphics primer before you go too far.