How do I enable root login with ssh? (SU)

If you are convinced that you really do want to reenable root login through ssh then you'll want to follow these two simple steps:

Open up /etc/ssh/sshd_config and set "PermitRootLogin" to "yes". (Your ISP probably set it to "without-password")
You also need to restart the sshd process. This is done by killing the existing one (use ps -aux|grep sshd to get the process ID, then use kill to zap it), then restarting /usr/sbin/sshd
Again, make me feel more secure. Make sure you really want to do this, and then make sure that you have a really solid, impossible to guess root password.