Texas Instruments TravelMate 4000M User Reference Manual page 219

Options
8.
9.
10. Slide the plastic cover over the drive until the plastic
12-18 Portable CD-ROM Docking System
Attaching SCSI connectors
Place the metal bracket over the drive so that the holes in
the feet on the plate are aligned directly over the holes
left by removing the screws.
Screw the bracket down.
Screw the metal plate over the drive
release tab clicks into place.