Put your straightener on the lowest setting it has, and let it heat up. Separate the doll's hair into several small pieces and lavishly spray a section. Proceed to straighten your doll's hair just like you would do your hair, making sure to pull it through her hair quickly. You do not want to let it rest anywhere on her hair, because chances are you would melt it.
When my mom and I finished, I was pleasantly surprised. Kaya's hair was silky. It's very easy to brush now, and looks so much better.
Thanks for looking!