your Q is so general and hard to answer. In fact, it depends on on the age of the child and also the bad behavior and also the root of his behavior. sometimes, children are just modeling their parents or an older brother or sister, for instance a child who constantly yells might be raised by parents who get angry easily. I think that at first you should find the root of his bad behavior to be able to solve it. Also. you can ask a psychologist or read psychological books

I Tink , firstly we can explain right way and then talk about our experiences with them. I found it effective

Only by examples. Besides children's personalities are made of society. So you can't change children's behavior till  you don't have changed the society.

I think we need patiently explain them situation and try to speak about different examples. We need to find with child what is wrong in examples and what is right and what consequences we will have if we choose this or that decision.

Dear, you only rephrased the question, but didn't give us the solutions :)