I have one more alternative to perform this task. Please follow below steps:
- Go to you theme folder i.e
app/design/frontend/your_package/your_theme/layout/page.xml
Find the code given below:
<block type="page/html_header" as="header">
And past the cart sidebar block shown below:
<block name="header" as="header">
<block name="top.links" as="topLinks"/>
<block name="store_language" as="store_language" template="page/switch/languages.phtml"/>
<block name="top.menu" as="topMenu"/>
<!--Add cart sidebar block -->
<block name="cart_sidebar" as="headerCart" template="checkout/cart/sidebar.phtml"/>
</block>
2. : And now, in template file header.phtml
(app/design/frontend/your_package/your_theme/template/page/html/header.phtml),
call cart sidebar block as a child in header
<?php echo $this->getChildHtml('headerCart')?>