Eliminate render-blocking JavaScript and CSS in above-the-fold content

for javascript add this code in your function.php file

// Adapted from https://gist.github.com/toscho/1584783
add_filter( 'clean_url', function( $url )
{
    if ( FALSE === strpos( $url, '.js' ) )
    { // not our file
        return $url;
    }
    // Must be a ', not "!
    return "$url' defer='defer";
}, 11, 1 );

there isnt easy way out to fix the css recommendation though.check this answer..
https://stackoverflow.com/questions/18761251/eliminate-render-blocking-css-in-above-the-fold-content