Where can I go to find information if I want to create or change a unit insignia?

The Civil Air Patrol Heraldry Guide provides information on how to create a unit insignia and the basic requirements for approval. You can download the guide here: http://history.cap.gov/files/original/69f796595f5ebe2c67634092021ad42e.pdf  If you have additional questions, contact the CAP Heraldry Manager, Lt Col Phil Kost, at philip.a.kost@gmail.com