HP TC4400 - Manual (Page 133)

5–50 Maintenance and Service Guide
Removal and Replacement Procedures
6. Release the ZIF connector to which the TouchPad cable is
attached and disconnect the TouchPad cable 1.
7. Slide the TouchPad 2 to the right and remove it.
8. If it is necessary to replace the TouchPad cable, disconnect
the cable 3 from the TouchPad board.
Removing the TouchPad
Reverse the above procedure to install the TouchPad.