Summarize:

These stainless steel kitchen utensils have sharper edges than regular zesters or graters and they are ideal for grating hard spices like nutmeg and mace. If you don't have access to this type of zester, use a nutmeg grater or a small zester. You need a very sturdy grater with small, hard holes to adequately grind the hard seed. Make sure they are sold in the shell. Once the shell is broken on the seed, the expiration date moves from nine years to three years. Smash it between the cutting board and a strong knife or plate. Don't worry about breaking the seed itself.  Grasp it on the plastic handle and rest the other end on the cutting board. It is best to try to keep your fingers as far away from the grater as possible. Repeat until you have a small pile of ground nutmeg on your cutting board. You can turn the Microplane over and wipe the back of it with your finger to harvest any nutmeg grounds that become stuck. For a light dusting on top of a cold or warm drink, hold the grater above a cup and use shorter motions. Freshly grated nutmeg is stronger than ground nutmeg.
Purchase a Microplane zester/grater. Buy a jar of whole nutmeg seeds. Crack the shell of a nutmeg seed open. Peel away the shell, cracking more shell as needed. Hold your Microplane or nutmeg grater at a 45-degree angle to your cutting board. Grasp the tip of the nutmeg seed with your thumb and forefinger. Slide the edge of the nutmeg in a fluid motion down two inches (5cm) of the grater. Use approximately three-fourths of the nutmeg measure that is called for in your recipe.