To remove the optical drive, unlatch and remove the base cover. Unlatch and remove the front bezel. Identify and slide the tab to unlatch the hard drive assembly.
Disconnect the cables and lift the assembly to remove it. Identify the optical drive and unlatch it to lift it out of the system. To reinstall the optical drive, place it back in the system and relatch it.
Reinsert the hard drive assembly and reconnect the cables. Relatch the assembly. Place the front bezel and base cover on the system.