These instructions show how to update Drupal core to a new minor version within the same major release series (for example, Drupal 7.1 to 7.2). These instructions are a simplified version of the corresponding information in the Administration & Security Guide.
Follow these instructions:
Make a backup of your Drupal instance (database). (For ex: with MySQL)
Download the latest release of your current Drupal version.
Extract the [tar ball or zip] Drupal package.
Set your site on maintenance mode (For ex: How on D7)
Delete all the files & folders inside your original Drupal instance except for /sites and its sub-folders. This assumes that all of your custom work - including themes - is in the recommended spot - the /sites folder tree. If you have made custom changes elsewhere you will need to either preserve them or plan to replace them later.
Copy all the folders and files except /sites from inside the extracted Drupal package [tar ball or zip package] into your original Drupal instance location.
Some updates do not include changes to setting.php and some do. See There is a way - Comment below for more on this. If the update release includes changes to settings.php you will need to replace your old settings.php in .../sites/default/ with the new one, and then edit the site-specific entries (eg database name, user, and password) in the setting file.
If you have modified files such as .htaccess or robots.txt re-apply those changes to the new files.
If you have a favicon.ico file that was deleted replace it too
Login to your site as administrator or as user no 1
Run update.php by navigating to http://yoursitename/update.php and follow the process to update your Drupal instance
Disable maintenance mode
Troubleshooting
If you experience problems during your site upgrade, see the Troubleshooting FAQ.
Instead of commenting here, please read the module project page and, if necessary, post an issue or post a message in the forums.
More information can be found on the Drupal site.