Someone

1)
chenged
cons25 to cons25r in /etc/ttys

2)
added this to /etc/rc.conf
font8x8="cp866-8x8"
font8x14="cp866-8x14"
font8x16="cp866b-8x16"
scrnmap="koi8-r2cp866"
keymap="ru.koi8-r"

3)added this to /etc/profile
LANG=ru.KOI8-R
export LANG
MM_CHARSET=KOI8-R
export MM_CHARSET