I don't know about this part:
After executing this step you are connected to your instance. We will have to install new packages. Some of them require root credentials, so you will have to set a new root password: sudo passwd root. Then login as root: su root.
Wouldn't using the "sudo su" command be a better approach? Granted I am only a developer not a sysadmin, but I thought the whole point of Ubuntu's sudo setup was to not have a usable root login.