Some grinders are very easy to clean. The Mazzers are a good example. The hopper and upper burr carrier can be removed from my Kony with no tools other than an opposable thumb. The Rancilio Rocky takes a bit more effort to get into. Normal, say weekly, cleaning can be achieved with a product like Urnex Grindz. About half of a coffee scoop should be sufficient for a grinder the size of Rocky.
      There are times when it is a good idea to access the grinding chamber. One example would be if the grinder has sat, unused, for a week or two, like when you go on vacation.
      Here are the steps for a thorough cleaning. It is designed so that you can return the grinder to as close to the grind setting you are currently using as is possible. Be aware that this is from memory since I no longer own a Rocky Grinder, so if there is anything here that you find wrong or needs further discussion, please E-Mail me):

• 1) Remove any beans in the grinder and run it until there are no beans left in the burrs.
• 2) Write down the grind number at which you have been grinding.
• 3) Without changing the grind setting, remove the three screws that you see holding the finger guard, down inside the bean hopper. There are probably beans stuck in the holes. Usually you can just crush them with the screwdriver, but a pick tool (dental or automotive) can be used as well. (Note: the screws are slotted, just in case they are so encrusted you can't see them.)
• 4) With all three screws removed you can lift off the hopper with the finger guard and its three screws.
• 5) There are three screw holes in the top of the brass, upper burr holder. Use a marker pen and make an indicator mark next to the screw hole hearest the front. On the paper where you wrote the grind number setting, draw a diagram and record where that screw hole is located in relation to the grinder.
• 6) Turn the upper burr carrier CLOCKWISE until it stops (the burrs should now be touching). On the same diagram, using another color pen, indicate the current location of the marked screw hole.
• 7) Now unscrew the upper burr carrier and remove it from the grinder. Use care not to drop it as it is heavy, the burr is sharp, and dropping it is good neither on counter tops nor feet.
• 8) Clean up as necessary. I usually use an old brewhead brush. Once clean, examine the burrs for chips, cracks, or dull edges. I can tell you that if your grinder gets used daily, the burrs are good for about two to three years. I always noticed the difference when I changed burrs.
• 9) Once the majority of filth is cleaned out, use compressed air to blow out the rest. Be sure to blow through the motor vents as well to get as much coffee out of the internals as possible. USE EYE PROTECTION!
• 10) Make sure that the threads of the burr carrier as well as the threads of the metal body of the grinding chamber are clean. Wiping with a clean, lint-free cloth will usually do it.
• 11) Wrap two turns of teflon tape around the threads of the burr carrier. Do not let the tape protrude off the bottom of the threads. You don't want this to end up in your coffee.
• 12) Place the upper burr carrier onto the grinder. Turn it counter-clockwise until the threads drop into place with a tactile click, then turn it clockwise to start the threads. Screw it in all the way until it stops. The marked screw hole should be close to the position as you recorded in Step 6.
• 13) Now loosen the carrier so that the indicated mark is at the position as you recorded in Step 5.
• 14) OPTIONAL STEP: If all this disassembly seems like more trouble than it is worth, try this:
  Turn the bean hopper over and remove the Phillips head screw that is protruding from the bottom. With that screw removed, next time all you will need to do is hold the adjustment button down and unscrew the entire hopper/burr assembly without tools. *1
• 15) Place the Bean hopper on top of the upper burr (having a third hand to depress the adjustment lock button can be a big help here. Turn the hopper so that the number recorded in Step 2.
• 16) Align the three screw holes. Note that you may not get the exact grind setting back, but it should be pretty close. *2 Once aligned, place the finger guard in place and start the three screws. Tighten them evenly. All they do is hold the hopper in place so there is no need to over-tighten.

*1- Be aware that with the stop screw removed from the bottom of the bean hopper it is now free to rotate if the adjustment lock button is depressed. If you press the button while grinding the hopper will spin wildly. In an extreme situation, the hopper can be ejected from the grinder. So, if the grinder is running never press the lock button without having a hand on the hopper!

*2- The grind numbers are meant only as an easy way to return to a previous grind setting and mean nothing on their own merit. If the same grind number is not indicated after disassembly you may need to readjust the grind. If you are replacing the burrs a new grind setting will almost always be needed.