urgent help needed passport expiry

Hi all

Need your help

My h1b petition is approved on June 16th. My passport is expiring in sept 2015.I have filed visa with old passport. I m planning to go for stamping in sept itself. I got my new renewed passport. Pls let me know how and when to update the new passport details. Do I need to take any proactive action before I go to stamping? Pls help me I m worried it will create a problem thanks alot