MYSQL root password change from 8.x

Update: On 8.0.15 (maybe already before that version) the PASSWORD() function does not work You have to do:

1. Make sure you have Stopped MySQL first (above).
2. Run the server in safe mode with privilege bypass: sudo mysqld_safe --skip-grant-tables
   mysql -u root
   UPDATE mysql.user SET authentication_string=null WHERE User='root';
   FLUSH PRIVILEGES;
   exit;
   Then
   mysql -u root
   ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'yourpasswd';