How to update WordPress: Automatic update
In WordPress 2.7.x you can easily update your application directly from the admin area. When a new version is available, you will see a notification in the WP admin area.
Before you proceed with the upgrade, we strongly advise you to make a backup of your WordPress.
When you are ready, click Please update now to proceed with the upgrade.
On the next page you can choose whether to upgrade automatically or manually.
Click Upgrade Automatically
If everything goes smoothly, your WordPress will be successfully upgraded.
How to Upgrade WordPress: Manual upgrade
Step 1: Backup the Database Tables and Files including .htaccess.
Step 2: Deactivate Plugins
Deactivate all the Plugins you use from the plugin management page.
Some plugins might not work with the new WordPress version and in order to avoid discrepancies it would be best to deactivate all plugins. This will ensure that you won’t end up with an upgraded but broken installation of WordPress after the upgrade process.
Step 3: Overwrite Files
- Overwrite option 1: Get the latest WordPress version from WordPress download page and upload it to the WordPress directory, overwriting all the files that exist there. This will preserve your images and themes.
- Overwrite option 2: Deleting your old files on the server and uploading the newer files from the new version you’ve downloaded is an alternative which will ensure that the files on the server have been replaced for sure.
Which option is better?
Generally, it is a good idea to delete whatever is possible because the uploading (or upgrading through cPanel) process may not correctly overwrite an existing file and that may cause problems later.
DO NOT DELETE these folders and files:
wp-config.php file; wp-content folder; wp-images folder; wp-includes/languages/ folder–if you are using a language file, do not delete this folder; .htaccess file–if you have added custom rules to your .htaccess, do not delete it; Custom Content and/or Plugins–if you have any images or other custom content or Plugins inside the wp-content folder, DO NOT delete them.
DELETE these Files and Folders:
wp-* (except for those above), readme.html, wp.php, xmlrpc.php, and license.txt; files; Typically files in your root or wordpress folder. Again, don’t delete the wp-config.php file. wp-admin folder; wp-includes folder; If using a language file remember don’t delete the wp-includes/languages/ folder wp-content/cache folder; You only see this folder if you are upgrading FROM WordPress 2.0.
Step 4: Run the upgrade script
Visit your blog’s Upgrade Page (http://yourdomainname.com/wp-admin/upgrade.php) and follow the instructions that are displayed.
Step 5: Reactivate Plugins one by one
Activate your plug-ins, one by one, at the Plugin Management Page. Check if everything works as expected.
If any plugin does not work, deactivate it and then you might contact the plugin author to encourage the author to upgrade the plugin.