Reducing the size of the header area above the banner image

Hello All,

I just installed 3.0.4 and am using the default 2010 theme which I am altering to suit the look of the blog to match the rest of the existing website.

All I want to do is reduce the empty space above the header image to 20px. That’s it. I know there are some changes I can make to the header.php file, are there changes that can be made to style.css to accomplish this?

I need someone experienced in editing the header.php file. All I need to know is how to reduce the area above the banner. Should be answerable in code here.

Many thanks in advance!

Sincerely,

wordman