Once the screw is out, you’ll be able to separate the two halves. The top half will slide back and the lower half slides forward. Be gentle though, the patient will thank you.
The inside was bit cleaner than I was expecting for three years worth of dirt but what you can’t see is the crud hiding under the scroll wheel. Yuck! The top half, not wanting to be left out, also had some gunk built up.
Alright now for an anatomy lesson…
With the two halve separated, you can use canned air or a soft brush to clean the four switches. You can also test that the switches are working by pressing the switches lightly, by with enough force to produce the mouse clicks.
To clean under the scroll wheel, you’ll want to remove the weight, also a phillips-head screw. Removing this screw will allow you to the lift the circuit board as well as let you remove the scroll wheel. With the scroll wheel out, you can get to the hair or whatever that has wound up on the scroll-wheel axle. In the cleaning of the scroll wheel, it’s very likely that you’ll clean up the tiny bit of grease thats on the right axle. A tiny (and I mean tiny) amount of axle grease can be added back.
With the top half, there are no electronics so you can hit that half up with some soapy water and a soft sponge or old toothbrush. After that, give the top half of the mouse plenty of time to dry before reassembly. You certainly do not want to introduce any water into the electronics.
Once your satisfied that everything is clean and dry, reassemble the mouse and fold back the felt. If you haven’t cleaned the felt yet, you can do so with some sticky tape; duct tape works well.
Once you’ve gotten everything back together, it should be working like new again, or at least mine is and has been now for a few days. You can also be happy with the knowledge that you saved $70 over purchasing a new one. Frugality gives us the true recycling and that’s repairing what we can.