An USB upgrade is the only way I can do it. That's not my computer, his connection is very slow and it would take ages to download it.
I had installed the Xubuntu 14.04 LTS via USB, now I'd like to upgrade it with the new 16.04 LTS. Some suggest to do a clean install, some say it's okay to upgrade from a LTS to another one. Could you help me? What file do I need if I can upgrade via USB? Many thanks