During the final year of his life, Manson spoke to a REELZ documentary crew from Corcoran State Prison about his cult and crimes through his own eyes.
In the promo clip, Manson can be heard saying "I'm the most famous human being not only that is alive, but the most famous human being that ever lived. And I'm not even dead yet. What do you think is going to happen when I die?"
The film, which was originally slated to premiere in 2018 but has been moved up to December, reportedly follows a new theory behind the murders.
"I never ordered nobody to do anything," Manson can be heard saying in the clip.
He continued: "I've been deep in thought in solitary confinement for almost 40 years, thinking, 'What the hell does all this mean? How does that fit? Where does that work?' And the stuff that I've come up with, man, it's just unbelievable."
Manson died on Sunday evening after his health had been in decline for the past year. He was hospitalized twice in the past year and died from "natural causes," according to authorities. He was 83 years old.
Final Words, narrated by Rob Zombie, airs Dec. 3 at 9 p.m. on REELZ.