Replace header.php with header.html

I have spent many hours trying to change header.php to achieve the look I want. This includes deleting the blog functions, deleting the search function, and adding a rollover image aligned with the title. It is still not done; the rollover doesn’t align with the title and a spurious “Submit Query” remains.

I would like to create a simple html page with the rollover image, title and banner image. No php It would link with my style.css file

How can get my child theme to look for header.html instead of header.php?

site: http://stmichaelspecialschool.com/?page_id=37

Thanks

Frank