Was remarkably easy to upgrade over SSH (which is good as I am not in the Linux command line world as often these days!) https://wiki.ubuntu.com/BionicBeaver/ReleaseNotes
Have also applied many of the hardening steps at:
Well worth a read if you are running Ubuntu and want to improve security. Not mentioned on there (probably as its more about using Ubuntu as an end user device rather than a server) is to review the SSH config and harden the SSH service.
