Modify header with html

Hello, I’m using a template by Phi – Andreas Wilthil called powerplay.
I’m trying to change the header from http://tunstullstudio.com/, which is actually a reference to a jpg: http://tunstullstudio.com/wp-content/uploads/2011/11/Logo234.jpg,

I’m looking at the header.php file and would like to insert html that points to an animation, http://tunstullstudio.com/Logo23/Logo23.html.

I’d like to know whether it’s possible and how to modify my header.php file to have it show if it is possible.

Thanks,
Art