How was The Other Side of the Wind released in 2018?

The 2018 release of The Other Side of the Wind was made possible by utilizing the original footage edited by Orson Welles along with his production notes.1

Although Welles shot and partially edited the film between 1970 and 1976, production stalled when funding was exhausted. The project subsequently became entangled in a protracted legal battle that persisted for decades following Welles's death.1