Texas Instruments 4000M - Manual (Page 217)

3. Remove the battery by pressing the release button and
sliding the battery out.
4. Remove the four screws beside the recessed area in the
battery compartment of the Portable CD-ROM Docking
System.
5. Open the SCSI drive kit. This should include a SCSI
connector, metal bracket, plastic cover, screws, and
installation instructions.
Battery release
Remove screws
Options
12-16 Portable CD-ROM Docking System