As shown in video above, add these codes to the bottom of the themes functions.php file. If you have a child theme then add it there. Any custom work should always be done in a child theme because when you update the core of WordPress these custom additions may be over-written.
But even easier is using the code snippets plugin as shown in video.
// remove wp version meta tag and from rss feed
function at_remove_wp_ver_meta_rss() {
return '';
}
add_filter( 'the_generator', 'at_remove_wp_ver_meta_rss' );
// remove wp version param from any enqueued scripts
function at_remove_wp_ver_css_js( $src ) {
if ( strpos( $src, 'ver=' ) )
$src = remove_query_arg( 'ver', $src );
return $src;
}
add_filter( 'style_loader_src', 'at_remove_wp_ver_css_js', 9999 );
add_filter( 'script_loader_src', 'at_remove_wp_ver_css_js', 9999 );