Before you begin updating your WordPress site, make sure that your database is data backed up so that no data is lost should you run into any problem or glitch during the process.
It is easy to update your application directly from the admin area. You will be notified when a new version comes up. You can choose between manual and automatic upgrading. The latter is recommended for a smooth, error-free and quick upgrade. You can also download the new version package first and then upload it.
At the end of the process, you will get a message that WordPress has been successfully upgraded.