Before disconnecting the thermal sensor cable, take note of its orientation. It is extremely important to reinstall the connector in the current orientation so the fans will not run at full speed. If you have multiple pins on your replacement hard drive, put the connector closest to the SATA connections and closest to the PCB board.

Disconnect the thermal sensor, SATA power, and SATA data cables by pulling their connectors away from the sockets on the hard drive.