mysql --user=my_username --password
CREATE USER 'username'@'localhost' IDENTIFIED BY 'password';
CREATE DATABASE `db_name`;
GRANT ALL PRIVILEGES ON `db_name` . * TO 'username'@'localhost';
SET password for 'username'@'localhost' = password('my_new_password');
Stop mysqld process
sudo mysqld_safe --skip-grant-tables &
sudo mysql --protocol=socket