Change the admin header from a plugin

Is there any way to make changes to the admin header bar (e.g. Change the ‘Howdy’ to something else), without editing admin-header.php?

I would like to include the change as part of a plugin, something along these lines:
—-
function replace($content) {
$content=str_ireplace(‘Howdy’,’Some other greeting’,$content);
return $content;
}
add_filter(‘admin_head’, ‘replace’);
—-