Young adult to child hair conversion?

I tried converting this hair style below from YA female to female child so I could use it on one of my sims, and I got to the point where I'm placing the hair mesh over the child's head in Blender. Unfortunately, there's a part of the mesh at the neck that sticks out. Can't do anything about it. Or maybe I'm not experienced enough to know what to do since this is my first time trying to do CC. So could someone please convert it to female child for me?

mystufforigin.blogspot.pt/2015/09/reys-hairstyle.html