Boot from cd rom using dvd centos installation and write “linux rescue” enter the following command until mount file image “chroot /mnt/sisimage/
Edit /etc/shadow to remove
if you can do this, just type “passwd” once you are in and change it to whatever you like. Or just edit /etc/shadow to remove the password field: move to just beyond the first “:” and remove everything up to the next “:”. With vi, that would be “/:” to move to the first “:”, space bar once, then “d/:” and ENTER. You’ll get a warning about changing a read-only file; that’s normal. Before you do this, /etc/shadow might look like:
and after, the first few lines should be:
You’ll need to force the write: with vi, “:wq!”.
write “Exit’. system automatically restart.