How to move Cart from Right Sidebar to Header in Magento?

Find the below line in your page.xml file.

 //Near line 70

Add the below code inside to that block

Your new code will look like this

        
        
        
            Navigation Bar
        
        
            Page Header
            top-container
        
	//new block 
	

Finally Add the below code in your "\template\page\html\header.phtml" file.

//place this where ever you want the cart to show up.
<?php echo $this->getChildHtml('topcart'); ?> 

Thats it. You can see the cart sidebar in your header section.