How to change password on Solaris 10 ( x86 & SPARC)

init 0 go to ok promt only for SPARC
ok boot -F failsafe
This one is for x86
#df -h
#mount /dev/dsk/c1t0d0s0 /a
#cp -p /a/etc/passwd /a/etc/passwd_1
#cp -p /a/etc/shadow /a/etc/shadow_1
#grep root /a/etc/shadow

It shows the beloow line
root:123e45r56:15478::::::    ------it should be removed

After editing the file should be like this
#vi /a/etc/shadow   
root::15478::::::

After inserting this and then save it and quit it
:wq!

bootadm update-archieve
umount /a
sync
sync
init 6

****** ** *** ** * * * * * * * * * * * ** * * * * ** ** * ** * * * * * * * * ** * * *

**For mirror disk check the both df -kh and mount them both.If you change into one mirror disk then the password recovery will not be happend. You have to check the both disk.
bootadm update-archieve -f -r /a