Install Samba package from ISO file or CDROM

I have an old server which is running Ubuntu Linux 16.04 in a lab environment. It is not not possible to upgrade to the new Ubuntu version due to hardware capacity. I decided to keep it and us it as normal (security issue is not a problem). I need to install samba package but I can't get this package from the repository anymore. I have an ISO file of this distro and also burn into a CDROM. I have checked the document about select the CDROM as the source of installation but when I tried to do that the system still keep asking me to connect to internet. I tried to review the configuration file many time but seem nothing wrong but I still can't install the samba package from this media. If anyone has any solution please kindly let me know how I can fix this problem or is there any offline .deb package that I can't install samba on my Linux? Thank, Kanel