Compaq LTE Elite Maintenance And Service Manual page 280

7. Flex the top cover of the expansion base downward [1] to slightly widen
the gap between the drive cages (Figure 9-36).
8. While the top cover is flexed, place the other end of the drive cage
spacer [2] into the slot on the other drive cage [3], and release the
tension on the top cover (Figure 9-36).