If you do not have the recovery mode option, this is the alternate way to manually edit the grub options to allow for a root shell.
First you will want to make sure to choose the regular boot kernel that you use (typically just the default one), and then use the e key to choose to edit that boot option.
Now just hit the down arrow key over to the
kernel option, and then use the
e key to switch to edit mode for the kernel option.
You will first be presented with a screen that looks very similar to this one:
You will want to remove the ro quiet splash part with the backspace key, and then add this onto the end:
rw init=/bin/bash
Once you hit enter after adjusting the kernel line, you will need to use the B key to choose to boot with that option.
At this point the system should boot up very quickly to a command prompt.
- Changing the Actual Password
You can use the following command to reset your password:
After changing your password, use the following commands to reboot your system. (The sync command makes sure to write out data to the disk before rebooting).
sync
reboot -f
I found that the -f parameter was necessary to get the reboot command to work for some reason. You could always hardware reset instead, but make sure to use the sync command first.
And now you should be able to login without any issues.