Complex sentence: It was their 8th video, and was released and premiered on June 21,2007at 100 locations in the U.S., 34 of them in California alone.
Split into simpler sentences: It was their 8th video, and was released on June 21,2007. The video premiered on June 21,2007 at 100 locations in the U.S., 34 of them in California alone.