You can modify the heading hierarchy or assign a level in the hierarchy to a custom paragraph style. You can also add chapter and section numbering to heading paragraph styles. By default, the "Heading 1" paragraph style is at the top of the chapter hierarchy.
Choose Tools - Chapter Numbering, and then click the Numbering tab.
In the Paragraph style box, select the heading style that you want to add chapter numbers to.
In the Number box, select the numbering scheme that you want to use, and then click OK.
Click at the beginning of the text in the heading paragraph, after the number.
Press the Backspace
key to delete the number.
Press Shift+Backspace with the cursor at the beginning of the heading to return the number.
Choose Tools - Chapter Numbering, and then click the Numbering tab.
Click the heading level that you want to assign to the custom paragraph style in the Level list.
Select the custom style in the Paragraph Style box.
Click OK.