How can i "modd" my xbox 360?

<div style="float:left;margin:5px;font-size:80%;"><img alt=""xbox 360 backups"" src="http://farm4.staticflickr.com/3592/3325691555_61d87f0de1_m.jpg" width="160"/><br/> by <a target="_blank" href="http://www.flickr.com/photos/34938425@N08/3325691555">humboldt111502</a></div>
<strong><i>Question by athan</i>: How can i "modd" my xbox 360?</strong>
i have an

Play Xbox 360 Game ...