Tips on Customizing VK All in One Expansion Unit

How to Hide VK All in One Expansion Unit Admin Menus

function plt_hide_vk_all_in_one_expansion_unit_menus() {
	//Hide "CTA".
	remove_menu_page('edit.php?post_type=cta');
	//Hide "CTA → CTA".
	remove_submenu_page('edit.php?post_type=cta', 'edit.php?post_type=cta');
	//Hide "CTA → Add New".
	remove_submenu_page('edit.php?post_type=cta', 'post-new.php?post_type=cta');

	//Hide "ExUnit".
	remove_menu_page('vkExUnit_setting_page');
	//Hide "ExUnit → ExUnit".
	remove_submenu_page('vkExUnit_setting_page', 'vkExUnit_setting_page');
	//Hide "ExUnit → Main setting".
	remove_submenu_page('vkExUnit_setting_page', 'vkExUnit_main_setting');
	//Hide "ExUnit → CSS Customize".
	remove_submenu_page('vkExUnit_setting_page', 'vkExUnit_css_customize');
}

add_action('admin_menu', 'plt_hide_vk_all_in_one_expansion_unit_menus', 21);

Where do I put this code?

How to Hide VK All in One Expansion Unit Meta Boxes

function plt_hide_vk_all_in_one_expansion_unit_metaboxes() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Hide the "VK All in one Expansion Unit" meta box.
	remove_meta_box('veu_parent_post_metabox', $screen->id, 'normal');
	//Hide the "Excerpt" meta box.
	remove_meta_box('postexcerpt', $screen->id, 'normal');
	//Hide the "CTA Contents" meta box.
	remove_meta_box('vkExUnit_cta_url', $screen->id, 'normal');
}

add_action('add_meta_boxes', 'plt_hide_vk_all_in_one_expansion_unit_metaboxes', 20);

How to Hide the "Vektor WordPress Information" Dashboard Widget

function plt_hide_vk_all_in_one_expansion_unit_dashboard_widgets() {
	$screen = get_current_screen();
	if ( !$screen ) {
		return;
	}

	//Remove the "Vektor WordPress Information" widget.
	remove_meta_box('vk_dashboard_widget', 'dashboard', 'normal');
}

add_action('wp_dashboard_setup', 'plt_hide_vk_all_in_one_expansion_unit_dashboard_widgets', 20);