In this instructable I will show you how to get rid of that (what I find to be annoying) click when using your Microsoft mouse scroll wheel. The only tools you will need are a small, sharp set of scissors (you might have better luck with a utility knife) and a small phillips head screw driver. I performed this on a Microsoft Wireless Optical 2000 mouse but I believe that most microsoft mouses(mice?) are built the same way.
Step 1: Disassembling the Shell
The two halves of the mouse are held together by a single screw located behind the battery door. After removing the screw carefully pull the two halves apart starting at the rear of the mouse.
Step 2: Removing the Wheel Assembly
Once the shell is removed you have easy access to the wheel and it's associated parts. The clip which holds the wheel in place will now rotate forward, up and away from the body of the mouse allowing you to pull the entire assembly free. This clip is held in by 2 small push-in hinges. Carefully pull them apart being careful to avoid damaging the optical sensor.
From here you can now remove the wheel from the clip that it rides in. The wheel is secured in the same manner in which the assembly is held to the mouse. Simply push it out of it's clips being careful not to break them.
Step 3: Silencing the Click
The small bar that rides the inside of the wheel can now be clipped away. I used a very sturdy, sharp pair of scissors for this task and had no problems. You may want to consider a utility knife for the job as it may be hard to find a pair of scissors that will fit into such a small area.
Don't worry about removing the entire bar. Just make sure that you've removed enough so that it no longer touches the inside of the wheel.
Again be careful not to break the clip itself or you might be without a wheel all together!
Step 4: Reassembly
You can now start piecing your mouse back together. If you followed these instructions carefully, you should be able to pop this thing back together with no problems.
When putting the wheel assembly back into the body of the mouse, be sure that it is in the right direction!
When you are ready to put the shell back together, slide the front of the 2 halves together first as there are 2 clips which need to mate before the rest of the mouse will fall back into place.
Replace the screw behind the battery door and you'll be ready to scroll through the longest page you can find with a quick flick!
(Sorry for the picture quality. Taken using my blackberry :x)