First of all check your model number, the effected models are 95065 and 95055. The picture below shows where to check.
First off, you need to place your X Plorer controller face down on a table or sturdy suface and remove all 11 of the black screws from the white body of the controller. You will need a long and thin screwdrive in order to do this.
Then once you've removed the back from the controller you need to locate the whammy bar's sensor mechanism.
The next step is to slightly loosen the two screws that hold the sensor in place.
Ok, this is where my tutorial differs. Now you need to plug your xbox controller into your windows xp computer. Then wait until it is installed and ready to use. Open your control panel then open the game controllers settings. You should see your X-plorer. Now open the settings for the controller.
Your X-axis is the whammy bar. Turn the whammy bar sensor left or right (while keeping the bar out all the way) until the red x-axis bar exactly reaches the top. Your whammy bar is now properly calibrated. You can move the actual bar while holding the senor in place to double check that it is in the right position.
Now retighten the two screws for the whammy bar and screw the cover back on. You now ready to rock out.
I discovered this, so please give me the credit if you wish to repost this information.