Connect null-modem-cable to the serial port
Reboot the server using the LCD display then
Select "Boot shell" (the last item), on the LCD display.
execute
        mount
        load /boot/vmlinux-2.4.27-r5k-cobalt
        execute root=/dev/hda2 console=ttyS0,115200 init=/bin/bash
When the system finishes booting
execute
        mount -o remount,rw /dev/hda2

then use the 'passwd' command to reset passwords