First, instead of changing the header/footer, consider changing what it displays using a
StyleRef Field linked to the style of the section's lead heading.
If a section's header is linked to the previous section, any changes apply to both sections. Link to previous is the default setting.
Sections / Headers and Footers in Microsoft Word 2007-2013
Note, with different first page and different odd and even settings checked, each section has three headers and three footers:
- The odd page header/footer (default header/footer)
- The even page header/footer (different even and odd checked)
- The first page header/footer (different first page checked)
Note, if you have those options checked, you have all of the header/footers in a section even if it only has one page. If you expand it, they will show up. If the next section is linked to this one, it will be using headers and footers that you do not even see in the one-page section.
That is an awful lot of headers/footers to be editing in each section. If you can use the StyleRef field and keep the section's linked, you will have far less editing to do.