Ok, I see now. You have to substitute the logo file for yours and if you don't want to show the tagline you have to delete the text.
Logo:
includes\templates\sophybluegr\images\zcLogo.jpg
To change the name and dimmensions:
includes\languages\english\sophybluegr\header.php
edit lines 21-25
There you will also see the tagline text. If you don't want to display it just leave it empty:
Remember I'm assuming you uploaded ALL the files included.Code:define('HEADER_SALES_TEXT', '');
Have fun!