IBM Aptiva Reference Manual page 106

102
3 From the back of the drive bay, carefully insert a 3.5-
inch disk drive then secure it with four screws on the
sides.
4 Re-install the drive bay into the housing as in the
following figure:
a Align the drive bay with the notch.
b Pivot the drive bay toward the housing until
the tab clicks into place.
.
5 Connect the signal and power cables to the drives.
Adding and removing drives