Tips on Customizing GeoJSON Maps

How to Hide GeoJSON Maps Admin Menus

function plt_hide_geojson_maps_menus() {
	//Hide "Settings → GeoJSON Maps".
	remove_submenu_page('options-general.php', 'geojson-maps/gm_settings_page.php');

	//Hide "Map Layers".
	remove_menu_page('edit.php?post_type=gm_layer');
	//Hide "Map Layers → Map Layers".
	remove_submenu_page('edit.php?post_type=gm_layer', 'edit.php?post_type=gm_layer');
	//Hide "Map Layers → Add New".
	remove_submenu_page('edit.php?post_type=gm_layer', 'post-new.php?post_type=gm_layer');
}

add_action('admin_menu', 'plt_hide_geojson_maps_menus', 11);

Where do I put this code?

How to Hide GeoJSON Maps Meta Boxes

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

	//Hide the "Layer Info" meta box.
	remove_meta_box('gm_meta', $screen->id, 'side');
	//Hide the "Layer Rules" meta box.
	remove_meta_box('gm_rules', $screen->id, 'normal');
	//Hide the "Popup Text" meta box.
	remove_meta_box('gm_popup', $screen->id, 'normal');
}

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