Upgrading your Joomla 1.5 website to RC4 Karibu

The short version can be found on the Joomla website which consists of the following:
Although a complete re-installation is recommended, it is possible to upgrade from RC3 to RC4 with the following procedure:

Backup all files; backup your database.
Delete all Joomla! core files, but leave any third-party extension files in place, including your configuration.php file.
Upload/copy contents of RC4 package.
Execute the MySQL commands to be found in /installation/sql/mysql/diff.sql to implement the necessary database changes.
Delete the entire /installation directory.


Backup all files; backup your database. The first line is VERY important, I will leave it at that.
	Delete all Joomla! core files, but leave any third-party extension files in place, including your configuration.php file. This step is very important and some files have been renamed and it could cause issues. Ask me how I know. See this post for an example of what I am talking about. Make sure you don't delete your configuration.php
	Upload/copy contents of RC4 package. I would exclude the installation directory to make it go a little quicker
Execute the MySQL commands to be found in /installation/sql/mysql/diff.sql to implement the necessary database changes.
UPDATE `jos_plugins` SET `ordering` = `ordering` + 1 WHERE `folder` LIKE 'system'; UPDATE `jos_plugins` SET `name` = 'System - SEF', `folder` = 'system', `ordering` = 1 WHERE element LIKE 'sef';
	For this your going to open PHPMyAdmin and select the SQL tab to execute a SQL query. If you are going from RC3 to RC4 you should only need to execute the teo following lines:
	If everything goes successful you should get a screen like this.