Can you describe the exact nature of the problem- is the hinge stuck, parts broken? Is the mount stuck in the open or closed position, or does it hang loosely? An image of the mouth area would help. These toys are have both metal and plastic components- the fix depends on which parts are affected and how.
As soon as you provide some images of the problem and more of a written description, I'll be able to answer your question.
Let me know if I can be of further assistance.
Please provide images and more description so I can answer your question.