The nib should be aligned centrally to the feed so that nib slit and capillary line up. An exchange is not necessary; the correction is done simply with two fingers (straightening the nib right and left), as would also happen in the boutique. Unlike on a Pelikan, where the nib is fastened via a metal ring and mostly has to be exchanged completely, the Montblanc nib seat cannot be unscrewed. If a laser marking on the clip is missing, the pen is presumably at least ten years old.