Step 1: Replace WordPress Files:
- Get the latest WordPress zip (or tar.gz) file.
- Unpack the zip file that you downloaded.
- Deactivate plugins.
- Delete the old
wp-admindirectories on your web host (through your FTP or shell access).
- Using FTP or your shell access, upload the new
wp-admindirectories to your web host, overwriting old files.
- Upload the individual files from the new
wp-contentfolder to your existing
wp-contentfolder, overwriting existing files. Do NOT delete your existing
wp-contentfolder. Do NOT delete any files or folders in your existing
wp-contentdirectory (except for the one being overwritten by new files).
- Upload all new loose files from the root directory of the new version to your existing wordpress root directory.
NOTE - you should replace all the old WordPress files with the new ones in the
wp-admin directories and sub-directories, and in the root directory (such as index.php, wp-login.php and so on). Don't worry - your wp-config.php will be safe.
Be careful when you come to copying the wp-content directory. You should make sure that you only copy the files from inside this directory, rather than replacing your entire wp-content directory. This is where your themes and plugins live, so you will want to keep them. If you have customized the default or classic themes without renaming them, make sure not to overwrite those files, otherwise you will lose your changes. (Though you might want to compare them for new features or fixes..)
Lastly you should take a look at the wp-config-sample.php file, to see if any new settings have been introduced that you might want to add to your own wp-config.php.
If you're upgrading manually after a failed auto-upgrade, it is possible that a .maintenance file was created. Delete the file from your WordPress directory using FTP. This will remove the 'failed update' message.
Step 2: Update your installation:
Visit your main WordPress admin page at /wp-admin. You may be asked to login again. If a database upgrade is necessary at this point, WordPress will detect it and give you a link to a URL likehttp://example.com/WordPress/wp-admin/upgrade.php. Follow that link and follow the instructions. This will update your database to be compatible with the latest code. You should do this as soon as possible after step 1.
If you have caching enabled, your changes will appear to users more immediately if you clear the cache at this point (and if you don't, you may get confuese when you see the old version number in page footers when you check to see if the upgrade worked).
Your Wordpress installation is now successfully updated.
Your update is now complete, so you can go in and enable your Plugins again. If you have issues with logging in, try clearing cookies in your browser.