Disassembly to allow cleaning the mouse wheel. A #8 Torx Tamper Proof Bit will be needed.
Remove the battery door and use a #8 Torx Tamper Proof Bit to remove the center screw. Pry the cover of the mouse starting from the back and lifting it up toward the wheel.
Remove the screw from the cover with a #1 Phillips. Unclip the two fins from the plate by lifting up on each gently. Remove the silver plate by prying the cover striaght up.
Gently lift up on the left shroud until it detaches. You can also detach the two side buttons. They are compression fit. Pry them each gently out of the hinge with a flat blade.
Be Extremely Careful There is a small spring between the housing and the base plate of the mouse. The ribbon cable that attachs the mouse wheel is tough to remove. It is compression fit without tabs. I needed to use a small flat blade screw driver to pry it out of the socket. The mouse wheel housing that clicks to the left and right is compression fitted on the bottom only. You can separate it from the other housing by lifting up on the bottom "hinge". The bottom housing is again a compression fit hinge attaching it to the base plate with spring.
The mouse wheel assembly comes apart easily.
The circuit board is all one piece that lifts straight out. As you lift out the circuit board push the battery terminals so they clear the base plate. The reset pin will come loose after the circuit board is removed.
Cleaning Time! Now all the plastic parts are separated you can clean them. I used a crest spin brush with simple green. Spray the large parts and then brush and rinse in the sink. For the smaller parts spray and brush over a container and then rinse in water in another container. Let all the parts air dry and use compressed air for the small parts before reassembling.