Apple Power Mac G4 Cube (Battery Replacement) - Manual (Page 5)

Power Mac G4 Cube Battery - 5
Replacing the Computer Core in the Enclosure
1 Holding the core by the latch, insert the core into the computer.
Note: The core fits into the enclosure only one way. Position the core
so the ports are toward the back of the enclosure.
2 With a flat hand, press down on the latch until it locks into place. Firmly
press the core to ensure it is fully secured within the enclosure.
Important: Do not lift or carry your computer by the core latch. The
enclosure could fall off the core and be damaged.
Core
Enclosure
Latch