Complex sentence: On February 15,2007 KKSN 910 AM changed their call letters to KTRO; and on March 28,2007, KTRO-FM changed their format to regional Mexican and changed their call letters to KRYP, and the existing talk format continued on KTRO 910 AM.
Split into simpler sentences: On February 15,2007 KKSN 910 AM changed their call letters to KTRO. On March 28,2007 KTRO-FM changed their format to regional Mexican (and changed their call letters to KRYP) and the existing talk format continued on KTRO 910 AM.