NEC 2000 Series - Manual (Page 90)

5-8 Solving System Problems
Typical mouse ball cover
A – Mouse Ball Cover
3. Rotate the ball cover counterclockwise and remove the cover.
4. Turn the mouse over so that the cover and ball fall into your palm.
5. Clean the mouse as follows.
T Use tap water, or tap water and a mild detergent, to clean the
mouse ball.
T Use a clean, lint-free cloth to dry the ball.
T Blow into the mouse socket to remove remaining dust or lint.
Use a Q-tip to remove accumulations of dirt.
6. Gently put the ball back into the mouse.
7. Fit the ball cover back into the mouse and turn the cover clockwise
until it locks in place.