Complex sentence: The HV units were replaced by the HVO on 11 October, when the Bočac Hydroelectric Power Station was captured and the HVO achieved the offensive's objective of reaching a line south of Banja Luka, advancing against disorganised VRS units retreating to Banja Luka.
Split into simpler sentences: The HV units were replaced by the HVO on 11 October. By the end of the day the HVO had captured the Bočac Hydroelectric Power Station the offensive's objective was achieved when the force reached a line south of Banja Luka.