Under "Edit Profile" should've been an option for leaving the community.
Am I looking in the wrong place?
You can only self-delete your profile if the profile has never voted and has posted at most once in the history of the account. If this is not true, the Delete Profile link will not be shown.
To delete a profile which does not meet this criteria, use the contact us link and choose ‘I need to delete my user profile’.
Practically, it's simpler to just anonymize your profile if that's what you want - deletion just automates the anonymization of your posts and profile. If you're asking about linking accounts - that's a different path: http://stackexchange.com/users/218740/bmike?tab=accounts