Things You'll Need
Instructions
Find pictures of your action figure with its head intact. You can use pictures of your own if you have them, or look up pictures of your figure on sites like the Action Figure Times archives (www.aftimes.com). This will serve as a guide to help you create an accurate-looking replacement head.
Melt some plastic. Use about a half teaspoon of plastic beads (the amount may vary depending on the size of your figure) and place them in a microwavable container of water. Heat the container for about two minutes until the plastic has melted (individual instructions may vary, check the packaging of your plastic). Remove the melted plastic with a fork: when it is fully heated, it should be completely translucent. It it remains cloudy, give it an extra 30 seconds in the microwave.
Attach melted plastic to the action figure's neck. After the plastic has cooled enough to touch, pull a piece and stick it to the shoulders of the action figure, either attaching it to any neck that exists or forming a new neck by pinching the plastic between your thumb and forefinger, then gently rolling.
Sculpt the head. Good tools to use for this include bamboo skewers, needles, toothpicks and other items with fine tips. Getting it just right is a matter of practice, but if you have some experience in sculpting, you should be able to make at least a serviceable replacement head. Your plastic will likely start to cool and harden before you're finished with your sculpture or have it just how you want it. Keep the cup of hot water on hand (refresh it every so often with a couple minutes in the microwave) and dunk the plastic briefly in it to re-soften it (the rest of your action figure shouldn't be harmed by this process, but if you're worried you can test it beforehand on a small piece of the doll).
Remove fingerprints. Once your head is finished and cooled, it will have the impression of your fingerprints on its surface. If you wish to remove these, do so by lightly and briefly touching the plastic's surface with the flame of a cigarette lighter.
Paint the head. Use acrylic paint, and for the best results, add a first layer of flesh tone paint, a second layer of hair color, then add in details like facial features using a very fine-tipped brush or a toothpick.