reset root and admin (local accounts) passwords with apple CD. reset open directory (LDAP) directory administrator password
sudo mkpassdb -dump | grep diradmin
this will give a slot no like this
slot 0001: 0x00000000000000000000000000000001
then type this
sudo mkpassdb -setpassword 0x00000000000000000000000000000001
enter the new password you good to go