The answer is actually on their website:
Put a rewrite rule like this on your .htaccess:
RedirectMatch 301 ^/(it|ko|zh-CN|zh-TW|pt|en|de|fr|es|ja|ar|ru|el|nl|zh|zt|no|bg|cs|hr|da|fi|hi|pl|ro|sv|ca|tl|iw|id|lv|lt|sr|sk|sl|uk|vi|sq|et|gl|mt|th|tr|hu|be|ga|is|mk|ms|fa)/(.*)$ http://www.mysite.com/$2