okay, so i executed the commands inside the directory where i put the downloaded files (desktop), unfortunately, i could no longer execute the last 2 commands because the i got this mac dead screen. Tried booting back either in single user, safe mode but to no avail. Im just greeted with the dead screen in the login menu. Is there anything i can do to fix this? I followed the instruction and used another command windows, login as administrator by typing sudo su.