Check the current locale settings and update to a new locale:

locale -a
update-locale LANG=en_US.UTF-8

Remove the Korean language upgrade message:

• /etc/update-manager/release-upgrades controls what updates you'll be notified about
• /usr/lib/update-manager/release-upgrade-motd generates the “update available” message. The message is cached, which means that once it's been generated, changing /etc/update-manager/release-upgrades doesn't get rid of the message.
• Tell Update Manager what releases you want to be notified about.
• # rm /var/lib/update-notifier/release-upgrade-available to get rid of the cached message.

# adduser <username>

To elevate the user to administrator, add him to the sudo group

# vim /etc/group

To allow the new user to login via SSH with a keypair, copy the public key to ~/.ssh/authorized_keys file. Make sure the directory and file is owned by the user, and group and others do not have permissions. If you need to create the public key first, follow this guide: SSH Client and Server.

Upgrade to Ubuntu 14.04 LTS with the following command:

# do-release-upgrade

You must make sure that a non-root user can SSH into the machine and obtain root permissions!

hostname <newname>

$ ubuntu-support-status