You might try very gently twisting the base in the wind direction to see if you can feel the rachet click at all. Then gently rock it back and forth just where the rachet wants to click and see if you can get it to release and go backwards thus releasing the spring.
If there is any chance you can get it apart, unlikely, you'd look for a large toothed gear type thing with a spring held piece that grabs the teeth. This is the rachet that is supposed to let you wind it only one way. You might be able to hold the spring loaded piece away from the toothed wheel and let the wheel go backwards. Gently is the theme here it's probably plastic and cheap. Good luck Tom
