Linux reset password (Debian based)
then follow the command to call bash on the next initialization after grub
rw init=/bin/bash
Wait to enter as $roort#
passwd [user]
For list user you can use (you find probably at end of the list):
less /etc/passwd
To restart you can’t use shutdown because it’s not started the OS itself, so use the following command to restart:
exec /sbin/iinit 6
This is only for study or necessity cases use at your own responsibility