How to take the help button and link off the dashboard

The code is in wp-admin/includes/template.php, function screen_meta(). However, there’s no hook to disable the help button, so if you want to get rid of the button, you’d have to use CSS or JS.

If you choose CSS, a

body.index-php .screen-meta #contextual-help-link-wrap { display: none; }

should do.

If you just want to get rid of the content, use the 'contextual_help' filter and return an empty string:

add_filter('contextual_help', 'my_dashboard_help', 10, 2);
function my_dashboard_help($help, $screen_id) {
    if ($screen_id == 'dashboard') $help = '';
    return $help;
}