Boot single-user from CD-ROM (boot cdrom -s)

Mount the root partition on "/a". "/a" is an empty mount point that exists at this stage of the installation procedure. For example:

#mount /dev/dsk/c0t0d0s0 /a


type #TERM=sun; export TERM
Edit the passwd file, /a/etc/shadow (or perhaps in older versions, /etc/passwd) and remove the encrypted password entry for root.

Type: "cd /; then "umount /a"