Thank you guys..
It works now.. i did the same thing like restore root password and it works
- insert CD (I think it can be ignored)
- send <break> on putty
- at '{3} ok' prompt I type boot cdrom -s, but i also can do 'boot -s'
- then restore manually by edit '/etc/passwd', '/etc/shadow', and '/etc/group'
- done
Thank you