Just be aware that there isn't a Waypoints book currently for the human factors subject, although there is Ross Ewing's Aviation Medicine book which I think is still available but starting to get a bit out of date with the current syllabus. But per the above comment it is most definitely possible to self study the subjects and many people do. Many aero clubs and flying schools are also happy to hire their instructors out for one-on-one tuition if there's a particular element of the syllabus you are having difficulty with.