Set your own custom logo on the WordPress login page. Upload your logo somewhere in your theme folder and reference it in the below code. Paste this code into your functions.php file located in your theme folder. Depending on the shape and size of your logo adjust the height and background size until it looks good.
function my_login_logo() { ?>
<style type="text/css">
#login h1 a, .login h1 a {
background-image: url(<?php echo get_stylesheet_directory_uri(); ?>/images/site-login-logo.png);
margin-bottom: 0;
background-size: 180px;
height: 180px;
width: 100%;
}
</style>
<?php }
add_action( 'login_enqueue_scripts', 'my_login_logo' );