At the bottom of the microphone is a large nut that holds the body together. There are two recessed spots that can be used to loosen/tighten the nut.

A simple wrench can be made from a scrap piece of wood and two small nails. Drill two holes 32mm apart in the wood with a bit smaller than the nails. Tap the nails in, and if possible, cut and sand the tips so that they are flat and of the same height (prevents slipping).

If the nails do not fit in the recesses, they can be bent until they do.

If the nails flex too much and slip out while tightening, shortening the nails will make them stiffer.