How to Update Drupal Modules

1. Put your website in offline mode inside your site maintenance mode.

2. Download the latest module from drupal.org.

3. Backup your database and module which you are going to replace, incase something went wrong. 

4. Replace that module with latest module that you have downloaded from drupal.org.

5. Go to your website and run update.php script . For example www.example.com/update.php .

6. Run the update steps and thats it !