Mysql 5.6 adds a method to modify username and password

shell> mysql --user=root mysql

mysql>CREATE USER 'finley'@'localhost' IDENTIFIED BY 'some_pass';
mysql>GRANT ALL PRIVILEGES ON *.* TO 'finley'@'localhost' WITH GRANT OPTION;
mysql>CREATE USER 'finley'@'%' IDENTIFIED BY 'some_pass';
mysql>GRANT ALL PRIVILEGES ON *.* TO 'finley'@'%' WITH GRANT OPTION;
mysql>CREATE USER 'admin'@'localhost' IDENTIFIED BY 'admin_pass';
mysql>GRANT RELOAD,PROCESS ON *.* TO 'admin'@'localhost';
mysql>CREATE USER 'dummy'@'localhost';

mysql>CREATE USER 'custom'@'localhost' IDENTIFIED BY 'obscure';
mysql>GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON bankaccount.* TO 'custom'@'localhost';
mysql>CREATE USER 'custom'@'host47.example.com' IDENTIFIED BY 'obscure';
mysql>GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON expenses.* TO 'custom'@'host47.example.com';
mysql>CREATE USER 'custom'@'%.example.com' IDENTIFIED BY 'obscure';
mysql>GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON customer.* TO 'custom'@'%.example.com';

mysql>DROP USER 'jeffrey'@'localhost';

mysql>SET PASSWORD FOR 'jeffrey'@'localhost' = PASSWORD('mypass');

mysql>SET PASSWORD = PASSWORD('mypass');