Logo in expositio theme

Hi,
I’m setting up a page using the Expositio theme from wpshower. I like everything about this theme except for the fact that I can’t figure out how to insert a .png for my logo instead of the text of the webpage title. I’ve looked for help on wpshower forums, but got no replies.

I know that I must insert a line with a piece of code directing to the logo file into my header.php, but I can’t figure out where and how. The attemps I’ve made have either ended with an error or with the logo appearing underneath the menu sidebar rectangle (partially hidden).

This is my webpage: . I would like to have my logo instead of the TARGONSKA/ZADRO?NY title.

And that is the piece of the header.php that (I suppose) is responsible for the title:

<title>
<?php
global $page, $paged;
wp_title( ‘|’, true, ‘right’ );
bloginfo( ‘name’ );
$site_description = get_bloginfo( ‘description’, ‘display’ );
if ( $site_description && ( is_home() || is_front_page() ) ) echo ” | $site_description”;
if ( $paged >= 2 || $page >= 2 ) echo ‘ | ‘ . sprintf( __( ‘Page %s’ ), max( $paged, $page ) );
?>
</title>

Can anyone help? Thanks!
Ola