I need to insert image banners into my WP single site installation

Hello, i’m developing the following website http://fullnews.gr and i want to insert horizontal image banners between the header and main content, exactly bellow the breaking news bar.

I’ve trying insertign the following code from a plugin <?php if( class_exists( ‘LenSlider’ ) ) {LenSlider::lenslider_output_slider( ‘5f719e4522’ );}?> inside the header.php and page.php and index.php files on various positions but it didnt worked.

Can you tell me where to to insert this line of code and in what file? I’m checking the theme’s files but havent found it yet..

Here is the page.php code http://pastebin.com/yEp4aKy2

Here is the index.php code


And here is the header.php code


Can you help me where to insert my code?

Thank you in advance!