If you want to delete the headers or footers defined in your document, follow these steps:

1. Position the insertion point in the section that has the header you want to delete.
2. Display the Insert tab of the ribbon.
3. In the Header & Footer group, click either Header or Footer, depending on which one you want to delete. Word displays a drop-down list of options.
4. Click Edit Header or Edit Footer, depending on which tool you clicked in step 3. Word displays the header or footer along with the Design tab of the ribbon.
5. Select the contents of the header or footer.
6. Press the Del key, or press Ctrl+X.
7. On the Design tab of the ribbon click on Close Header and Footer.

You may wonder why you don't just click Remove Header or Remove Footer, options available after you complete step 3 of these steps. The reason is simple—in my testing, clicking those options removes the header or footer text, but it doesn't remove the header or footer paragraph. Thus, if you have (for instance) a header or footer that includes a paragraph border, that border is still visible after you use the Remove Header or Remove Footer tools. The only way to get rid of the entire thing is to follow the steps as outlined.

If you are using a version of Word prior to Word 2007, follow these steps instead:

1. Position the insertion point in the section that has the header you want to delete.
2. If you are using Normal or Outline view, choose Header and Footer from the View menu. In Print Layout view, you can simply double-click on the Header or Footer you want to delete. You will see the Header and Footer dialog box, and the header area of the page.
3. If you want to delete the footer, click on the Switch icon in the Header and Footer dialog box.
4. Select the contents of the header or footer.
5. Press the Del key, or press Ctrl+X.
6. Click on Close.