Open /etc/ssh/sshd_config with your 'ee' text editor
ee /etc/ssh/sshd_configFind this
#PermitRootLogin noChange to
PermitRootLogin yesPress escape, and then choose yes for save confirmation.
Finally, restart your ssh daemon
service sshd restart...and done. You can login with root remotely over ssh.
Source:
http://blog.bobbyallen.me/2011/07/22/how-to-enable-root-login-over-ssh-on-freebsd-8-2/