Remove tagline from banner?

I think you are talking about the title from address bar, because I see no tagline in your header.

If I am correct, go in header.php and search for

<title> you have some code here, post it back on forum if you are not sure if you want to change it</title>

You need to have there:

<?php the_title(); ?> | <?php bloginfo(name); ?>

where:

<?php the_title(); ?> – is title of page/post

| – is delimiter can also be -

<?php bloginfo(name); ?>– is the blog title. you can replace this with any custom text