For russification ssh session edit config csh.cshrc.

# vi /etc/csh.cshrc

setenv LANG ru_RU.UTF-8
setenv LC_CTYPE ru_RU.UTF-8
setenv LC_COLLATE POSIX
setenv LC_ALL ru_RU.UTF-8

Write and quit.

Reboot server.

# reboot

For russification main console edit loader.conf.

# vi /boot/loader.conf

And add module vt.

kern.vty=vt

Write and quit.

Reboot server.

# reboot

For russification Gnome go to locale.conf file.

And edit it like this.

LANG="ru_RU.UTF-8"
LC_CTYPE="ru_RU.UTF-8"
LC_MESSAGES="ru_RU.UTF-8"

Write and quit.

Reboot server.

# reboot