I'm not sure that I should even be answering these, and they've been hanging around for a long time.
Basically, these questions are just too general to answer meaningfully in anything short of several
courses in philosophy and psychology. But I'll give you some really simplistic answers. 1) Study
science and philosophy of science. Don't study religion. 2) Encourage them to question their beliefs
and to study science. 3) By exercising it. That's the only way. Start by doing something you know you
need to do for, say, 20 minutes a day. Over a period of months, increase that time gradually.