There are different ways to change the password of MySQL account. They are:

1. Changing password using UPDATE statement:

For this you need to go to the User table of mysql database. To change password you need to execute the following commands:

USE mysql;

UPDATE user 
SET password = PASSWORD('your_password')
WHERE user = 'username' AND 
      host = 'hostname';

FLUSH PRIVILEGES;

For example:

UPDATE user 
SET password = PASSWORD('your_password')
WHERE user = 'root' AND 
      host = 'localhost';

2. Changing password using set password:

SET PASSWORD FOR 'username'@'hostname' = PASSWORD('your_password')

3. Changing password using GRANT USAGE statement:

Following statement is used to change the mysql account password :

GRANT USAGE ON *.* TO username@hostname IDENTIFIED BY your_password