How to update Wordpress

This article is a short description of the original documentation : Upgrading Wordpress

1. backup (database and file)
2. deactivate all plugin
3. rename the wp-includes and wp-admin directories
4. preserve the content of the wp-config.php
5. OVERWRITE all files even if they are the same date
6. go to http://example.com/wordpress/wp-admin/upgrade.php.