I have made a screencast to show how do we use the background removal feature in Microsoft Office 2010. This is one of the more common questions which teachers asked me when we were presenting at Yishun Town Secondary School
If you want to give it a try, you can download the sample files from here
http://cid-29f099c37b76ca59.office.live.com/self.aspx/Blog/Office%20Demo/Remove%20Background%20Sample.zip
Should you have any question, please feel free to contact me at [email protected]