How have Scrooge's supernatural experiences changed him?

To answer this question, take a look at stave 5 of the story, and you'll notice lots of changes. Firstly, Scrooge is excited about Christmas. Instead of saying "bah, humbug," Scrooge is keen to celebrate the day and sends a boy to fetch a goose for dinner.
Secondly, Scrooge is generous, as we see when he gives Bob Cratchit a pay raise. The old Scrooge would never have treated Bob so well and, in fact, was very annoyed that Bob asked to have Christmas day at home.
Thirdly, Scrooge is warmhearted towards his nephew, Fred. Scrooge calls at Fred's house, for example, and asks to have Christmas lunch with him. This compassion also extends to Tiny Tim, to whom Scrooge becomes a "second father." Remember that the old Scrooge actively avoided interactions and relationships with others.
These examples prove, therefore, that Scrooge's character was transformed by his supernatural experiences.