Upgrade Drupal Versions and Modules

Steps to Upgrade drupal minor version.

1. Backing up the site,
2. Putting it into maintenance mode
3. Downloading the new version of the module
4. Uncompressing it
5. Running update.php
6. Testing the site
7. Taking the site out of maintenance mode
8. Steps to Upgrade Drupal major version.

Backup your existing site and database.

1. Log in as user ID 1
2. Put your site in maintenance mode
3. Change all themes to Garland
4. Disable non-core modules
5. Remove default settings file
6. Remove all old core files and directories
7. Remove uninstalled modules
8. Download Drupal 7
9. Re-apply modifications to core files
10. Make your settings.php file writeable
11. Run the update script
12. Backup your database
13. Upgrade fields
14. Update contrib modules and themes
15. Check the Status Report
16. Make sure settings.php is secure
17. Check Drupal Core Modules
18. Remove your site from Maintenance Mode