Christopher Plummer (88) says he felt a "little dodgy" when he first arrived on the film's set to replace the erased Kevin Spacey.
British director Ridley Scott's new crime thriller All the Money in the World delves into the 1973 abduction of the teenage grandson of billionaire magnate J Paul Getty.
It's a re-telling of the true story of how Getty, the richest man in the world at the time, refused to hand over one cent toward the $US17 million ransom an Italian crime gang was demanding.
There's plenty of drama.
However, the behind-the-scenes twists, turns and tension Scott endured making the movie, and the race to have it ready for cinemas, almost exceeds the drama in the film's plot.
Oscar winner Kevin Spacey was the star of the film.
Prosthetics helped turn Spacey into the eccentric billionaire Getty, filming ended in August and for months trailers featuring snippets of the actor's powerful performance were released to whet the public's appetite and lay the platform for an assault on Hollywood awards season.
In late October Spacey became one of numerous high-profile Hollywood men accused of sexual harassment and assault.
Scott and the studio behind the film, Sony, faced a crucial decision.
They could release the film with the dark cloud over Spacey, scrap the film or shelve its release until the controversy died down.
Or they could take the bold move of erasing their star and attempt re-shoots with a new lead actor with the aim of still making the film's December 22 release date in the US.
After 36 hours of crisis talks they pursued the last option.
"Get rid of this guy - replace him immediately," Scott, recalling his mindset, told AAP in an interview in Los Angeles.
They recruited 88-year-old Canadian Oscar winner Christopher Plummer to take on the J Paul Getty role and then embarked on an ambitious nine-day schedule in Britain and Italy involving 400 new shots.
It added $US10 million to the already tight $US40 million budget and the film's other stars, including Michelle Williams and Mark Wahlberg, agreed to return for the re-shoots.
"It was actually fun, believe it or not," Plummer laughed.
The veteran actor tapped into his decades of performing on stage to quickly learn and recite the large slabs of dialogue.
"It was a little dodgy in the beginning because I thought, 'I have to learn all of this stuff' because he never stops talking - JP Getty," Plummer said.
"I found my theatre training helped me a lot in the memory department."
Scott, the 80-year-old director who broke through with 1979's Alien and went on to make classics Blade Runner, Gladiator, Black Hawk Down, Hannibal, American Gangster and The Martian, says he still managed eight hours sleep a night while pulling off the unprecedented last minute feat.
With his artist's background he drew storyboards for each shot so his actors and battle-hardened crew knew exactly what he wanted.
Instead of the dark cloud of Spacey destroying the film, the studio's Oscar marketing team has turned the negative into a positive by using the swift decision to erase and replace Spacey as a key part of their advertising campaign.
The film appears on track for Oscar nominations, with Scott, Plummer and Williams receiving Golden Globes nominations.
