Well, this is geuinaly not so helpful if you also lost your data encryption password.
break in
we gonna use bash as init⦠by modifing the kernel cmd line.
press βeβ key on desired Linux boot entry in grub or systemd-bootd, and overwrite correspond params with these:
rw init=/bin/bash console=ttyS0 earlyprintk=ttyS0and boot.
and jumped in to a root shell.

and you can run passwd as much as you like it.