The definition of analysis is "separation of a whole into its component parts." Therefore, an analysis of the plot of a book will involve breaking down that plot into the separate elements that are contained within the book. To get you started:
The exposition presents the characters in the story. You would identify protagonist, antagonist, narrator, and other important individuals. You would explain how they are involved with each other.
The rising action presents the conflict, the reason for the story's existence. You would analyze the protagonist's actions while working to achieve his/her goal in the story.
is the turning point of the story, where the main character makes the single big decision that defines the outcome of their story and who they are as a person.
You would describe the actions and reactions involved.
Identify each of the components of the plot of the book and analyze them.