Hide widgets/plugins from dashboard

WordPress SEO

If you want to remove the admin menu:

you can do that with:

function hide_wpseo() {
       remove_action('admin_menu', 'zeo_options_menu');
}
add_action( 'init', 'hide_wpseo');

where it will be removed for all users.

WordPress SEO by Yoast

To hide the admin menu:

and the admin menu bar:

one can use:

function hide_yoastseo() {
    remove_action('admin_bar_menu', 'wpseo_admin_bar_menu',95);
    remove_menu_page('wpseo_dashboard');
}
add_action( 'admin_init', 'hide_yoastseo');

where it will be hidden for all users.

Custom Content Type Manager

Here one can hide the admin menu:

from all users with:

function hide_cctm() {
    remove_menu_page('cctm');
}
add_action('admin_init', 'hide_cctm');