Why dont you try out these methods and see if they'll work.
1. Never scream at him.
It will instill fear in his mind, which later in life comes out in the form of no confidence, fears, phobias and mental problems.
2. Talk to him.
Solve your problems decently by talking to him face to face. Try to make him understand the issue by trying to come down to his mental level. Give him reason and logic. Screaming, yelling and hitting hum will only result in grugdes and stubbornness.
3. Talk to him by getting down on your knees, looking in his eyes and face to face.
This is because the child feels inferior to you when you are standing and you are looking down to him, as he is obviously quite smaller than you in height.
4. NEVER scare your child of anything.
For example, many parents scare their kids with Ojuju and stuffs. This will not help in anyway as there is no Ojuju anywhere. Suppose he does something wrong and the ojuju you told him never appeared, don't you think he will stop believing you? The fear of Ojuju can also result in psychological problems, fears and phobias.
5. Never lie to your child.
For instance, we are going for shopping (when in truth you are not) or i’ll come back in two hours (when you plan to spend the whole day there) and never ask him to lie, for example, tell someone at door that you are not at home etc. Parents are the only people in the world whom a child trusts blindly and he always looks up to them as inspiration but when you lie to him and he gets to know the truth, he will never ever trust you again. Asking him to lie will make lying a normal thing for him and he will become a guiltless lier and would lie to everyone, even YOU!
6. Maintain your voice while talking to him about his behaviour.
Don’t go too soft as this will over-normalize the situation. Don’t sound apologatic as this will give the upper hand to the child. NEVER shout. On the other hand NEVER smile. Talk to him in a stern, firm, serious and moderate voice as if you are talking in an interview or talking to an employee. Talk to him in a respected way, as not to hurt his dignity but make this clear that you are his parent and he HAS to listen to you and HAS to respect you. And you want no nonsense.
7. If the sitaution gets too out of control, try the naughty corner! Naughty corner is a place where there is no entertainment for the child.
It’s a corner in a room (in which you spend most of you time) where the child has to sit for 5 minutes or more whenever he misbehaves (Always keep them in the same room in which you are, NEVER send him to another room, NEVER lock them in a room). If the child run before that time, just simply do it again. And if ge gets more reckless increase the time in the naughty corner. Tell him that you will keep on increasing the time until he serves the time he is told and apologizes after that. (Don’t let the time go beyond 10-15 minutes, most of the kids will be tamed under that time.) When he apologizes, forgive him and hug him.
These methods will not only boost the child's confidence but also give him the feeling of being rewarded.