With your document open, display the Outlining tab. On the View menu, click the Outline button. Type the topic you want to demote. Type the topic at the main level, but don't press Enter when you're done.

What is the shortcut key for demote icon?

You can also demote and promote shapes from within the task pane. With the insertion point in the task pane, press the Tab key to demote a shape. Press the Backspace key (or Shift+Tab) to promote a shape.

How do you promote or demote a list?

Demote or Promote a List Item By Pressing Tab or Shift-Tab. Start by placing your cursor at the beginning of the line you want to demote or promote. To demote that line to a lower list level, just hit your Tab key. You can also demote a line more than once by just pressing Tab however many times you need.