To remove the hard drive, unlatch and remove the base cover. And front bezel of the system. Then flip the front panel over to access the internal components of the system. Identify the hard drive and disconnect the cables. Unlatch and remove the drive from the system.
To reinstall the hard drive, place it back in the system and relatch it. Reconnect the cables, flip the front panel over and latch the front bezel and base cover on the system.