It is really very simple on the Series CM2110 w/ Dual optical drives. Flip the unit over and look for two mounting screws for the DVD drive or Optical drive next to the PCMCIA port. Remove the screws and remove the optical drive. You will see a plastic mounting tray held in by two screws. Remove the screws and remove the tray holding the HDD. You will have to pull out then up to remove the drive. For installation, reverse the procedure.