The nibs fitted to the Pelikan Souveran and Classic ranges have interchangeable nibs which can normally be easily removed from the barrel by simply unscrewing. The below video shows you how to do it.
Please note, if the nib does not want to be unscrew or the pen is quite old, it may need to be soaked in warm water to help it loosen up.
We advise not forcing the nib and also holding it as low down as you can to minimise any twisting of the nib and ink feed. If you are unsure, please don't try it and seek professional help to get it removed.