Complex sentence: Manfred firmly dissociates himself from any such implication (unlike the film "Heaven's Gate", in which historical names are used to populate a radically fictionalized incident), going so far as to change even the names of the county and the nearby towns.
Split into simpler sentences: Manfred firmly dissociates himself from any implication of historical accuracy (unlike the film "Heaven's Gate", in which historical names are used to populate a radically fictionalized incident). He went so far as to change even the names of the county and the nearby towns.