Trace the second cable, the power cable, back to the power supply unit.

If the cable can be removed from the power supply without removing any other cables, then the power supply is modular and the unused SSD cable can be safely removed.

If the power supply is not modular, tuck the unused SSD cable into space next to the power supply. Use a zip tie to secure it out of the way, if needed.

Slide the side panels of the case back into place, and secure with the appropriate screws as necessary. The solid-state drive has been successfully removed from the PC.