1) To extract the dowloaded archive, open a terminal and navigate to directory that contains it (probably, ~/Downloads, but could be elsewhere) Type: tar -xzvf .tar.gz (substituting the achive name for "") (This step may have been done automatically by your operating system.) If your version of tar does not accept the "z" option to include unzipping, do the following: gunzip .tar.gz tar -xvf .tar 2) Change into the newly created directory ("Nlx_MED_Acq", "read_MED", "NRD2MED", "CSC2MED", or "DHN_License_Tool"): Type: ./install.sh The script may prompt for your root or sudo password to complete installation.