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:

• the text file /etc/update-manager/release-upgrades controls what release upgrades you'll be notified about, defaults to “lts”
• remove /var/lib/update-notifier/release-upgrade-available to get rid of the Korean upgrade 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.

After testing SSH access with <username>, disable root login with password in /etc/ssh/sshd_config:

# vim /etc/ssh/sshd_config
PermitRootLogin without-password
UsePAM no
# /etc/init.d/ssh reload

hostname <newname>

$ ubuntu-support-status