1. Find an application suitable for editing documents.

2. Open the document editor application. Locate and click the document editor icon in the application list, and then wait for the application to load.

3. Import the document to edit. Look for the option of "import" or "open" in the editor interface, select the location of the document, such as mobile phone memory or cloud storage service, and then select the document file to edit.

4. Divide the document into several chapters. Look for the "Split" or "Chapter" option in the editor's toolbar or menu. When this option is selected, the editor will automatically use the title or specific delimiter in the document as the chapter identifier.

5. Edit the chapter. Find the chapter list or directory in the editor interface, and click to enter each chapter for editing.

6. Save and export. After editing the chapter, click the Save button in the editor interface to save the modified document to the mobile phone memory or cloud storage service.