How to get Extended Security Maintenance for Ubuntu 16.04
Solution 1:
Setup Ubuntu 16.04 ESM
I tried out ESM on Ubuntu 14.04, (16.04 activation should be the same). It was pretty easy to set up.
I started out by installing an Ubuntu 14.04.4 ISO I had in my downloads folder. (I probably should have downloaded ubuntu-14.04.6-desktop-amd64.iso from https://releases.ubuntu.com/14.04/). Latest release of 16.04 is 16.04.7 LTS available from https://releases.ubuntu.com/16.04/. At this point we at least know for a fact that the downloading of 14.04 and 16.04 Desktop and Server is fully supported by Canonical.
During the install process I selected the option to download updates while installing. I think that if I would have used point release 6, there might have been fewer updates and the process might have gone faster.
It was a pleasure to log into 14.04 after so long, sort of nostalgic.
First priority was security. For 14.04 and now 16.04, this means signing up for Ubuntu Advantage (UA) client and installing ESM.
The Ubuntu discourse page for information on installing Ubuntu ESM is https://discourse.ubuntu.com/t/ubuntu-advantage-client/21788. the page directed me to https://ubuntu.com/advantage where I completed the registration process and ended up with a free token.
Back on https://discourse.ubuntu.com/t/ubuntu-advantage-client/21788 I continued with Installing the UA client by running a couple of commands as instructed. Next I proceeded to Attach the UA client. I ran the line I got when registering sudo ua attach [UNIQUECODE], (Please use your own free token).
Running sudo ua status I confirmed that ESM was enabled.
I completed the upgrade by running sudo apt update and then sudo apt upgrade. The installer ran for quite a while.
I ran Software Updater and It installed quite a few security updates. All Settings/Overview tells me System Up-To-Date.
It appears to me that Canonical is truly continuing support of Ubuntu 14.04 and 16.04 for free. I understand that Ask Ubuntu will not be allowind questions about ESM versions of Ubuntu?
AND EVERYTHING WAS FREE
Solution 2:
In-case you get the 401 Unauthorized error (like I did) after following all instructions correctly... This error appeared when trying to download any packages from esm through cli or software updater.
I restarted (no effect)
sudo ua detach
https://login.ubuntu.com/
Service Auth screen, yes log me in. I then reattached with code from Ubuntu site, started working now.