Complex sentence: She worked with concerned citizens to form the Bell Association to Stop the Abuse (BASTA), a local advocacy organization that forced Bell's corrupt officials out of office and ushered in accountability and transparency for the first time in the city's history.
Split into simpler sentences: She worked with them to form the Bell Association to Stop the Abuse (BASTA), a local advocacy organization. BASTA's efforts forced out Bell's corrupt officials, and ushered in accountability and transparency for the first time in the city's history.