have a Witch of Stolen Souls with a non-working head? As in it is not moving and the eyes do not light up?

I had that problem and was successful in fixing it.

Step 1 – Remove the Head
the head is simply plugged into the body with two fixed mounted plugs. Lift it off the body.

Step 2 – Surgery
in order to fix it we need to get inside the head. To do this you need to detach the rubber from the mask at the base. it is glued to the base but you can carefully pull the rubber off the glue

Step 3 – find the problem
Inside you will see a low voltage motor. two wires go to the contacts on the motor and chances are one of them broke loose from the constant movement. Resolder the wire and you should be done.