After five years in a university computer lab, this mouse wouldn't respond to clicks very well, but after this two minute repair job, it's as sharp as it's first day!
All you need is a bad clicky mouse, like the one pictured, a phillips screwdriver, and a nail file.
Step 1: remove the screw
There's only one screw in this model.
Step 2: Take the top off
Using gentle pressure and careful motions, start at the back, and wiggle the mouse unti the top comes off. The top is attatched pretty tightly but it's just snapped together, you can pull it open, but be careful not to break it!
Step 3: Remove the buttons
The buttons are one piece of springy plastic, held in to the top by a couple of springy plastic barbs. Push the barb back with your thumb and pull it past with your other finger.
Step 4: Chck it out!
Make sure you're careful not to get the scroll wheel loose of it's springs. It's very hard to put back.
If you look at the back of the buttons you'll see some little indentations. These are caused by constantly being crushed into the little actuators inside the mouse by ham fisted, computer illiterate, college "students," whose parents money would have been better spent renting them an apartment in Mexico and sending them daily beer deliveries. These also are the root of the clicky-no-clicky problem.
Step 5: File it flat and reassemble
Use the nail file to flatten the surface where the indentations are. Be sure no raised areas exist which might prevent the actuators from being depressed once it is assembled. Reassembly should be easy unless you took the scroll wheel out. Now is also a good time to clean out any bits of people that have accumulated inside the mouse (icky!).