Complex sentence: On October 15,2006, the tone of the messages changed, with Drew saying (via the account) "I don't know if I want to be friends with you anymore because I've heard that you are not very nice to your friends".
Split into simpler sentences: On October 15,2006, the tone of the messages changed. Josh/Drew said, "I don't know if I want to be friends with you anymore because I've heard that you are not very nice to your friends".