The font size of the pdf is intentionally very large (18 point for the most part) so that it can be printed in “booklet” form. To do so you need a printer that prints both sides of a page. When you click on the print selection in the pdf file menu, look for the “booklet” option. Also check the “page setup” to make sure that it is set for 100%, so when the printing software formats it for the booklet option it is readable.
To complete the booklet you need only to staple at the spine (which requires a long arm stapler) or simply fold the printed pages in half and keep them loose.