Help, how can I reduce the height of the header section in Pinboard theme?

Hello,

I want to reduce the height of the header part in my site and then make my logo and search bar go up a bit –> http://screencast.com/t/3O8tSjizzpD

In what part of the theme editor should I edit to come up with that desired display? and what code should I use for it?

I want to reduce the header part since it take up much space. Pls. help! I didn’t find a code that’s working.

Hoping for your response.