You can edit the headers and footers using Document Management.
In an open document, select the Add-ins tab then click the Customize Document Header and Footer button on the Document Management toolbar.
Edit or add information within the dashed lines that designate headers and footers.
Click Close on the Header and Footer toolbar when you are finished editing.
& NOTE: Headers and Footers are different on the first page than on subsequent pages of the document. It is standard to not have Headers or Footers on the first page of a document.