Some time ago we had a problem with Wordpress and could not automatically update the core files from 2.7 to 2.84. As a result we had to manually install the latest version of Wordpress. The Wordpress website explains "Automatic Upgrades do fail sometimes so remember to backup your database first, and deactivate your plugins before starting the upgrade".
After searching the Internet for a quick and easy solution we found this 7 point plan which worked perfectly. The Enkays-7-step-upgrade-to-wordpress-2-8-4 was a real find and here's a copy of the post (slightly altered for clarity).
Create a backup of the blog files on your FTP server and deactivate any plugins you are using with Wordpress. This backup must include all the Wordpress files in the main root folder as well as the wp-admin, wp-content and wp- includes folder. If you are using a web design tool, such as Adobe Dreamweaver, just rename the Blog folder to something like Blog_Old.
Create a backup of your MySql database just in case something goes wrong. This is needed because you might need to update your database once you complete upgrading Wordpress. Don't worry, this won't erase any of your posts, the process just needs to update the table structure. Here is Wordpress specific Tutorial as to how to backup your database. Depending on your website company, you may or may not have PhpMyAdmin but the process will be quite similar no matter what you use.
Download the latest version of Wordpress and unzip it onto your desktop. Rename the folder to something more appropriate e.g. Blog and place it where it needs to be for uploading to your server.
Using an FTP tool delete your existing Blog's wp-admin folder and wp-includes folder. Now copy to your server the new wp-admin and wp-includes folders as well as all the files that belong in the root folder. Do not copy over the wp-content folder otherwise you risk losing essential data such as uploaded images, themes etc.
Compare your old wp-config.php file in the root folder, to the wp-config-sample.php that is in your new Wordpress Blog folder. Check to see if there are any changes in structure. If there are, open the wp-config-sample.php and save it as wp-config.php. Now copy over all the data (sign up details, authentication unique keys etc) from your existing wp-config.php file into the new wp-config.php file. Upload the new wp-config.php file to your Blog's root folder.
Browse over to www.yourblog.com/wp-admin and log in. You might be asked to update your database which usually takes 2 seconds and then you will be logged in to the new upgraded version of Wordpress.
Sit back, relax and enjoy!
Thanks to enkays-7-step-upgrade-to-wordpress-2-8-4 for a great post.
This step by step upgrade is one of the easiest we found and its even better than the Wordpress.org version.
We would only add one step and that is to log in as ' admin' into your Wordpress Blog before you upgrade. Make sure your at the dashboard so you can see the 'nag to upgrade' to the next version. Now manually update the blog using steps 1 to 5 above and refresh the view. You might be asked to update your database at this stage, but this is soon done.The message nagging you to upgrade will now disappear and you will see before you the new upgraded version of Wordpress.
This way of doing the upgrade certainly worked for us and we hope that you find it easy to do as well. Why not print a copy of this page to help you focus on what needs to done.
WARNING: when upgrading WordPress 2.8 to 2.9, please make sure your hosts are running MySQL version 4.1.2 or higher before you do anything else.Read more articles about PC repairs, Web design & SEO...