Coles microphones in the UK used be able to send you a new ribbon , its not all that expensive if your willing to try the fitting yourself ,might cost £10 depending on model microphone .They have a large catalogue of ribbon specs in house ,so they can make them for the specific mic you have .
The ribbon arrives on a cardboard former which holds the shape and tension ,it allows you to drop it into place on the magnet assembly .
You could try dissasemble ,most likely that ribbon will fall appart , compressed air can be used to blow out the debris , I've also used a lump of blu-tac to trap and remove stubborn particles from the gap.
Metal or a magnet will tend to be pulled into the magnetic gap , so even when using the screw driver be very carefull ,