My chihuahua won't eat unless hand fed. How can I stop this habit?

A healthy dog will not starve itself, pick a spot to feed her and put her food down, hand feed her just enough to get her started then leave her to her food, after ample opportunity for her to eat take the food up. It shouldn't take very long for her to get the idea.
Be certain to offer her food at least twice a day and make sure she is drinking enough water.