Hi :)

I'm fairly new to CC4 so please bear with me. I created a character but the skin around the neck region is not blended/matched up between the head and the body. Please see the image, look around the neck region on the characters right shoulder, you'll see a line where the skin of the head and body does not match.
I've tried following online guides etc but I can't get it to match, I'm scared of messing it up alltogether to be honest. The character is right now part of an app that people have bought, it bothers me that the neck area is like this, I'd love to fix it for them in an update.
Any help would be very much appreciated. I considered myself to know the basics of CC4 but don't seem to know enough about skin to fix this.