LOS ANGELES — In a highly unusual move, the director Ridley Scott decided on Wednesday to remove Kevin Spacey from a finished movie, “All the Money in the World,” and refilm scenes with a substitute actor.

It will be a race against time: Mr. Scott promised Sony Pictures Entertainment that the altered film, which will now feature Christopher Plummer in Mr. Spacey’s role as the reclusive oil tycoon J. Paul Getty, will be ready in time for a scheduled release on Dec. 22.

The entertainment trade news site Deadline reported the casting change on Wednesday; it was confirmed by spokesmen for Sony and Mr. Scott.