Your Royal hates water! Never use water to clean, or wash your Royal under the faucet. Even exposure to moisture can cause surface oxidation to the steel burrs.
Simply use the provided cleaning brush to dust the burr retainer/underside of the burr set and wipe out the catch cup with a clean, dry cloth.
For deeper cleaning:
You may wish to remove your cone burr for a deeper clean, once in a while: Do not remove burrs until after 30 grinds, to allow them to "season" and break-in.
After this break-in period:
1. Before removing the cone burr, it is important to set the Royal to a coarse setting.
2. Secure the crank assembly with one hand, and use the provided 4mm hex wrench to loosen/remove the bolt securing the burr retainer to the axel. The burr will now drop out.
3. A dust blower tool (commonly used for cameras) can help to remove powder from the hard to reach areas inside the Royal body, but generally, the provided cleaning brush is all you will need.
4. Once dusted to your satisfaction, align and insert the prongs on the bottom of the burr retainer to those on the burr. Align the flats on the axel with the flats on the burr retainer during installation.
5. Tighten the bolt to secure them to the axel.
Note: Your Royal should remain on a coarse setting for the entirety of this process.
For a video demonstration, review this video.