Matthew's Journal

I don't remember which instructions I used when I deleted my own account, but both of these posts seem clearly written:

http://www.groovypost.com/howto/security/permanently-delete-your-facebook-profile-account/
http://www.wikihow.com/Permanently-Delete-a-Facebook-Account

The important thing to grasp is the difference between deactivation (which is easy, and useless) and deletion (which is harder, and what you want to do).