You have a complicated situation because you have a baby and a problem 6 year old and limited help from your husband.
If when daughter had a problem with 6 year old, if she left for 5 minutes and came back and resumed play, that would probably change the 6 year old's behavior over a week or two. She could go to her room and close the door if need be. But would she do that?
You could offer to negotiate with him, he is old enough to do that. Give him a chance to come up with solutions. If he has a few successes with that, that might help. Also, when he gets angry and yells, be stubborn about following through with actions, but don't debate, argue, or get into a verbal battle of wills. Show him that yelling and anger gets him nothing and collaborative problem solving is better for him. (Always keep the door open to collaborative problem solving with him long-term even if it does not work at first.)
You could use planned ignoring, not try to calm him down, just make sure he gets nothing, no attention or face-time for yelling and anger. That could change him in two weeks, but you'd have to deal with the baby waking up, but that might be the best alternative. A white noise machine near where the baby sleeps might help.
Also if he ever behaves well, even in a small way, show him you notice, talk with him about it when he engages in behavior that you want. Ask him to help in small ways and give him attention in the context of his being kind and helpful.
Last edited by tadamsmar; 06-23-2014 at 08:41 AM.