Answer:
It would change because it wouldn't be told from that character's point of view anymore, it might be biased because said character is the narrator, and if said character were to be just a character, you wouldn't see it from that characters point of view anymore.
Step-by-step explanation:
If you don't understand, think of how a story has multiple sides and how a story might be told differently from another person's side. This statement can apply to most books as well.