Complex sentence: In 1966 he returned to El Salvador, where he got a job in the Externado San José where he was a teacher and academic coordinator until 1967, when he started teaching at the Universidad Centroamericana "José Simeón Cañas" (UCA).
Split into simpler sentences: In 1966 he returned to El Salvador, where he got a job as a teacher and academic coordinator at the Externado San José. In 1967, he started teaching at the Universidad Centroamericana "José Simeón Cañas" (UCA).