Wordpress Single Site Configuration
Click on Wordpress in the Components menu to begin the Wordpress install process.
Next, you will fill in your site name, email and choose wether you would like search engines to index the Wordpress site individually apart from the main Joomla installation in which you just installed Wordpress or ask them not to (it is up to the search engine to honor the request).
Click the Install WordPress button to install WordPress.
Wordpress will now install. Once completed (can take a minute or two), you will see the final confirmation page.
You may now log into your Wordpress site that sits inside of your Joomla installation. Use the same username and password as you just used in the initial login to install Wordpress.