Wps version, double-click the header and footer to enter the editing state, select "Header and Footer" on the Insert tab to delete the content, and click the Close button on the far right to stop displaying the header and footer.

Word version: click the "View (V)" menu above->; Select "Header and Footer (H)" →; Enter the editing status of header, and the menu of header tools will pop up. After selecting all the contents of the header (press Ctrl+A to select all), click Delete to delete the contents-> After deleting the contents, click Close (c) in the Header and Footer menu.