Complex sentence: On December 6,2011, Universal Parks & Resorts announced that it would be open The Wizarding World of Harry Potter at Universal Studios Hollywood, and that one of the attractions would be Harry Potter and the Forbidden Journey.
Split into simpler sentences: On December 6,2011, Universal Parks & Resorts announced that they would be opening The Wizarding World of Harry Potter at Universal Studios Hollywood. They announced that one of the attractions would be Harry Potter and the Forbidden Journey.