You can delete a tag only if you created it or are identified by it. From your profile, access Photos, locate the tagged photo, then click the trash can icon and click Delete to confirm.
Once a tag has been deleted, it will no longer appear in the yearbook or on your profile. Please note, however, that deleting tags does not prevent members from tagging you again in the future.
Tags are also deleted automatically if the member identified deletes their profile, for whatever reason.