Complex sentence: Slightly less than one year later he returned to active, replacing sacked José Antonio Camacho at CA Osasuna: his first game in charge was a 4--0 home win against RCD Espanyol.
Split into simpler sentences: Slightly less than one year later he returned to active, replacing sacked José Antonio Camacho at CA Osasuna. His first game in charge was a 4--0 home win against RCD Espanyol.