Ive had to do this more than I care to mention. I should really know it by heart now, but the short version is:
- boot into the
grub
menu and select advanced options - head into recover mode
- drop to
root
shell prompt - you’ll need to remount the filesystem that is currently read only:
mount -o rw,remount \
- change the password:
passwd <your-username>
exit
- you’re done, reboot.
For a guide with pictures,