Related entries plugin question

Hi! I’ve seen this plugin Related entries and I’ve found it very interesting. The problem is that a don’t know how to do the modifications. The readme file says this:
———————-
1. Add a full text index to your wp_post table:
ALTER TABLE wp_posts ADD FULLTEXT post_related (
post_name ,
post_content
)
This is best executed using php admin tool.
2. Drop recent-post.php in your /wp-content/plugins/ directory.
3. Activate the plug-in through WP interface.
4. Put the following lines in your index.php, where your want related posts to appear:
<?php if ($single) { ?>

<?php related_posts(); ?>

<?php } ?>
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I entered my DB through MyPHPAdmin. I went to the wp_posts table but i don’t know how to ADD FULLTEXT post_related… Hope you can help me. Maybe this is obvious, but i don’t have idea. Thanks!