WordPress: WordPress In Your Index.php
Step 01.
Copy the code under and paste onto a new page using whatever editing program you use.
<?php /* Short and sweet */ define('WP_USE_THEMES', true); require('wordpress/wp-blog-header.php'); ?>
Step 02.
Save the new page as index.php. Open your FTP program and upload the file into your main directory.
Step 03.
Log into your wordpress dashboard and go to settings. Find where it says Blog Address (URL) and change http://www.yoursite.com/(the subfolder where you installed wordpress) to http://www.yoursite.com. Save the settings and now your wordpress blog will be in your index!