Add a image into the header to replace text

Hi there, I would like to add a image to my header.php instead of the default text. Unsure how to achieve this in php and wordpress. The website (link to image) I want to add is http://www.speedypinoy.com/speedypinoy.png. This would replace the default text and move the description text below. I have tried a few things but can’t get any results apart from destroying the rest of the theme. Thanks for your help 🙂