Reset root password on an ESXi 4.1 host

According to VMware KB http://kb.vmware.com/kb/1317898, root password cannot be reset without re-install.  Below is the a trick to reset the root password on an ESXi 4.1 without re-install.

1. Boot the ESXi host with a Linux boot-able media (e.g. DVD)
2. Mount the ESXi host partition containing the system data
• mkdir -p /tmp/mnt
• mount /dev/sda5 /tmp/mnt
3. Extract the shadow file of the ESXi installation and reset password
• mkdir -p /tmp/workdir
• cd /tmp/mnt
• cp state.tgz /tmp/workdir
• zcat state.tgz | tar xvf -
• zcat local.tgz | tar xvf -
• cd etc
• vi shadow "Reset the root password"
• cd ..
• tar zcvf local.tgz etc
• tar zcvf state.tgz local.tgz
• cp state.tgz /tmp/mnt
• sync; sync; sync
• umount /tmp/mnt 
4. Reboot the box