>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
2. Remove the keyboard assembly (Section 3.7).
3. Using a Torx T-8 or flat-bladed screwdriver, remove the screw from the
front right-hand corner and the left rear corner of the trackball
assembly (Figure 3-39).
4. Disconnect the integrated optical trackball assembly from the system
board by pulling upward on the trackball assembly.