Leave the code if you are not familiar, just go to styles.css and look for:
directly underneath add
That hides the title.
Now look for:
and then directly beneath that like before add:
That hides the tag line and moves the banner to the top.
Now if you want to get rid of the small space above it look for this:
padding: 30px 0 0 0;
and change 30px to 0 like this:
padding: 0 0 0 0;
Or change to 20px so that it all looks even as there is 20px padding to the left & right.
To redisplay the title & tagline, just remove the display:none;