如何仅在购物车中更改woocommerce每个产品的总数

I have my checkout cart like this

product price quantity total

apple 50 1 50

orange 40 1 40

I need to change the total on the right side to say 20

Code I tried i will put on comment box

but it changes the price.I only need to change the total.Any ideas?

Try with this piece of code in the functions.php file:

if(is_cart()){
    add_action( 'woocommerce_before_calculate_totals', 'add_custom_price' );

    function add_custom_price( $cart_object ) 
    {
        global $woocommerce;
        $custom_price = $_POST["custom_prc"];

        foreach ( $cart_object->cart_contents as $key => $value ) 
        {
            $value['data']->price = $custom_price;
        }
    }
}