How to remove your Youtube account
Youtube calls this ‘closing your account’, creating some unclarity: does the account still exist, somewhere? According to another source, your videos remain online (so if you wish, delete those first). Anyway, fill in some reason for closing your account and there you go.
Direct removal link: http://www.youtube.com/account?feature=mhum#manage/delete
Helpful Trick: Removing online data
Helpful Trick: Remove third-party logins
If you signed up for Youtube using a third-party login such as Facebook or Twitter, you probably want to revoke all access from Youtube. Click here to find out how.