Select or tap the page at the beginning of a section.
Select Layout > Breaks > Next Page.
Double-click the header or footer on the first page of the new section.
Select Link to Previous to turn it off and unlink the header or footer from the previous section.
Note
Headers and footers are linked separately. If you're using headers and footers that are different for each section, turn off linking for both header and footer.
Go the start of the next section and repeat steps 1-5. Continue for all sections.
Double-click the header or footer in each section and choose styles or add content.
Select Close Header and Footer or press Esc to exit.
For more on headers and footers, see Headers and footers in Word.