Q: How to change GRUB menu password if forgotten?

1. Read General Notes

2. grub
   
   grub> md5crypt
   Password: ****** (ubuntu)
   Encrypted: $1$ZWnke0$1fzDBVjUcT1Mpdd4u/T961 (encrypted password)
   grub> quit
   
   sudo cp /boot/grub/menu.lst /boot/grub/menu.lst_backup
   sudo gedit /boot/grub/menu.lst

3. Find this line

   ...
   password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/
   ...

4. Replace with the following line

   password --md5 $1$ZWnke0$1fzDBVjUcT1Mpdd4u/T961 (encrypted password above)

5. Save the edited file (sample)