Update delivered laptops?

I was asked, if and how already delivered laptops should be updated to new Lubuntu releases. In this case laptops were delivered to a school in Africa (based on 12.04 LTS and 14.04 LTS), now there is 16.04 LTS available. It is hard to answer this question, as an answer depends on the IT experience of helpers, the infrastructure (online access possible at edoovillage?) and other aspects.

The 1st rule in IT - Never touch a running system :) So be very careful to modify laptops in foreign countries without any access to web.

If you decide to start an update keep in mind that (L)Ubuntu stopped support for hardware in actual releases, but were supported in the past by former versions. And the hardware will be very different (size of HDD, speed of CPU, 32/64 bit, CD/DVD drive (or none) etc.). So you will have to download and take with you several images, which fit to the hardware abroad.

Other approaches beside cloning images will not work, as you are only able to install a basic (L)Ubuntu, but no extensions or content. So this would stay a partial solution.

Feel free to download and store to a local device up-to-date images and content to be taken to the edoovillage. You should prepare and test your equipment at home (you might have no access to internet at site). Read and store locally the wiki pages which might be helpful to you. Go through the installation process several time at home to get experience. Don't connect this laptop to web, simulate the situation abroad.

In worst case you have to consider bringing the laptops back to a hub and return it after updating.

From 2014 ff. the tool apt-offline was included into the Labdoo images for cloning. This tool might be helpful to you. You are able to download .deb-files etc to install them at site.
EN: http://manpages.ubuntu.com/manpages/precise/man8/apt-offline.8.html
DE: http://debiananwenderhandbuch.de/apt-offline.html

There is no final recommendation, if an update should be tried or not.