For disassembly special tools are needed (e.g. via penboard.de, item number 09736); a suitable block can also be made oneself. To loosen the piston mechanism the grip section must first be unscrewed; since grip section and barrel are glued with shellac, the pen must be heated with a heat gun at about 120 degrees until the adhesive softens. Care must be taken not to overheat the celluloid, since otherwise it becomes soft and can be destroyed. The cork must subsequently be replaced. On maxpens.de a photo of a fully disassembled Meisterstück can be found as a reference.