If you only have a few pages to edit or change and you're not concerned about affecting any page or section numbering, then you can simply select the pages using the selection tool, right-click (or Ctrl-click on the Mac) and choose Export Selection As... from the context-sensitive menu.
Then, make your changes as necessary in Word or Excel and create a new PDF of the pages. Next, use the Replace Pages command in the Page Thumbnail navigation pane to update the pages in your original PDF document.
