If I were trying to update a server with no internet access, I would install the programs I wanted to a 14.04.3 installation that does have internet access.
Then all you have to do is copy all the .deb files in that /var/cache/apt/archives/ to the /var/cache/apt/archives/ folder on the server. Then you can install the programs in the normal way - the download part is complete.
It is a good idea to run the command
Code:
sudo aptitude autoclean
before copying the .deb files.
If you don't want to actually install the programs on the connected computer, you can download the necessary .deb files without installing, by using the "download only" option.
Code:
sudo aptitude install --download-only newprogram
Then proceed as described above...