For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Scrooge is angry, snappish, mean, miserly, and hates Christmas and people who are happy. No one that he knows can change him.
Act II
A ghost and three spirits take him here and there to show him scenes from his own past, from the lives of those around him, and from his horrible future to make Scrooge realize what a mess he has made of his life.
Act III
Scrooge is shocked by the revelations, changes his ways entirely, and becomes a wonderful person and, more importantly, a Christmas lover.