Laravel - Help refactoring store method

I have a laravel application and in a certain store method, there are 128 lines of code. I need to refactor things that are repeating. I have a vague idea on how to do this but I'm not sure. This is the whole code (Do have in mind, Its really large).

public function store(Request $request)
{

    $selectedPlugin = null;
    $selectedPlugins = array();
    $price = null;

    foreach($request->input('plugin') as $key => $value) {
        if ($value === 'selected') {
            $selectedPlugin = $key;

            $plugin = Product::find($selectedPlugin);

            if($plugin == null)
            {
                break;

            } elseif ($plugin != null) {

                $price += $plugin->price;

                echo "ID: " . $plugin->id . "<br>";
                $selectedPlugins[$plugin->id] = $plugin->toArray();

                $request->session()->put('chosen_plugins.' . 'PluginID' . $plugin->id, $plugin->toArray());
                $request->session()->put('chosen_plugins.' . 'PluginID' . $plugin->id .'.composer_package', $plugin->productable->composer_package);
            }
        }
    }

    if(session()->exists('chosen_plugins') == true) {

        $products = Session::get('chosen_plugins');

        if(session()->exists('chosen_theme') == true)
        {

            $products['theme'] = Session::get('chosen_theme');
            $themePrice = Session::get('chosen_theme')['price'];
            $subtotal = $price + $themePrice;
            $vat = 21/100 * $subtotal;
            $priceSum = $subtotal + $vat;

        }  elseif (session()->exists('chosen_theme') == false) {

            $subtotal = $price;
            $vat = 21/100 * $subtotal;
            $priceSum = $subtotal + $vat;

        }


        $order = new Order;
        $order->user_id = Auth()->id();
        $latestOrder = Order::orderBy('id', 'DESC')->first();
        $order->order_nr = '#'.str_pad($latestOrder->id + 1, 8, "0", STR_PAD_LEFT);
        $order->sub_total = $subtotal;
        $order->vat = $vat;
        $order->price_sum = $priceSum;
        $order->save();

        foreach($products as $product) {

            $orderItems = new Orderitems;
            $orderItems->order_id = $order->id;
            $orderItems->product_id = $product['id'];
            $orderItems->price = $product['price'];
            $orderItems->save();
        }

        return redirect()->to('/ordersummary/'. $order->id);

    } elseif (session()->exists('chosen_plugins') == false ) {


        if(session()->exists('chosen_theme') == true)
        {

            $theme = Session::get('chosen_theme');

            $subtotal = $theme['price'];
            $vat = 21/100 * $subtotal;
            $priceSum = $subtotal + $vat;

        }  elseif (session()->exists('chosen_theme') == false) {

            $subtotal = 35;
            $vat = 21/100 * $subtotal;
            $priceSum = $subtotal + $vat;

        }

        $order = new Order;
        $order->user_id = Auth()->id();
        $latestOrder = Order::orderBy('id', 'DESC')->first();
        $order->order_nr = '#'.str_pad($latestOrder->id + 1, 8, "0", STR_PAD_LEFT);
        $order->sub_total = $subtotal;
        $order->vat = $vat;
        $order->price_sum = $priceSum;
        $order->save();

        if (session()->exists('chosen_theme') == true) {

            $orderItems = new Orderitems;
            $orderItems->order_id = $order->id;
            $orderItems->product_id = $theme['id'];
            $orderItems->price = $theme['price'];
            $orderItems->save();

            return redirect()->to('/ordersummary/'. $order->id);

        } elseif (session()->exists('chosen_theme') == false) {

            return redirect()->to('/ordersummary/'. $order->id);
        }

    }

}

As you can see, A lot of the code is repeating itself. Things like creating the order and defining the prices. These can be a lot cleaner. Besides that, the code is working perfectly fine. Also, the whole method is a big IF-statement. How can I refactor this method so it looks clean and the repeating pieces of code are no longer present?

Thanks in advance!

via Chebli Mohamed