You need to use:

a) A console, or

connect a PC/notebook in the serial port using the apropiate serial cable:

1) If the Serial console use an RJ45 as Serial conector
use the cable provided with the machine, or
if you use cisco switches use the terminal DB9
(for the PC an the cisco cable to serial 1)
2) If the Serial console use an DB25 connector as
Serial conector use the cable provided with the
machine, or an HP Serial cable DB9 to DB25

Because the most common case is to use a serial connection
the rest of the post is


b) Open an Hyperterminal/SecureCRT or whatever and
open a connection via COM1 (9600-8-N-1-None) using vt100
emulation.

c) Send a shift-break to halt the system

d) at the ok prompt
OK boot cdrom -s

e) After boot
TERM=vt100
export TERM
mkdir /tmp/d0
mount /dev/dsk/c0t0d0s0 /tmp/d0
cd /tmp/d0/etc

f) Leave blank the second field of the /etc/passwd
vi /tmp/d0/etc/passwd
( delete the x an save :wq! )

g) reboot

h) when prompt for root passwd press enter

i) change root passwd
passwd.


Note: If possible that you need to run an fsck
example: fsck -F <FSTYPE> -y /dev/rdsk/c0t0d0s0
FSTYPE: usually ufs

Note 2: If you use Solstice Disksuite in order to mirror
boot disk, you need to copy the modified /etc/passwd
to the other partition. I.E.:

f.1) mkdir /tmp/d1
mount /dev/dsk/c0t1d0s0 /tmp/d1
cp -p /tmp/d0/etc/passwd /tmp/d1/etc/passwd