How to transplant a Barbie head and neck to a Dragon Female figure. (Amy or Abbey)
First select your victims.  I used Amy and Kayla.
I lined up the chins of the two heads and made a dotted line on Kayla's neck. I carefully removed Kayla's head and cut on the dotted line.   The barbie neck  has a support inside. I dremeled it out carefully, trying to avoid the bottom of the neck post for the head.
Next, I had to modify Amy's neck post to accept the Barbie neck. I had to grind a bit and test the fit, Grind. Test. Etc until it fit properly.
Next I glued the two parts together and filled in the slight gap with Milliput. I did some sanding when the milliput was dry and painted the post to blend the the head and body.  I had the hardest time with mixing a matching paint color. The color wet was different from the dry paint color.  This was my first attempt so it was a learning process.
This is Kayla with her new body. Someday she'll get a Saree.  She will need to wear a turtle nesk or a necklace to hide the joint. The paint is rubbing off a bit at the collarbones.