src/Traits/ShopCartTrait.php
public function remove($item, $quantity = 0)
    {
        // Get item
        $cartItem = $this->getItem(is_array($item) ? $item['sku'] : $item->sku);
        // Remove or decrease quantity
        if (!empty($cartItem)) {
            if (!empty($quantity)) {
                $cartItem->quantity -= $quantity;
                $cartItem->save();
                if ($cartItem->quantity > 0) return true;
            }
            $cartItem->delete();
        }
        $this->resetCalculations();
        return $this;
    }
public function remove($item, $quantity = 0)
    {
        // Get item
        $cartItem = $this->getItem(is_array($item) ? $item['sku'] : $item->sku);
        // Remove or decrease quantity
        if (!empty($cartItem)) {
            if (!empty($quantity)) {
                $cartItem->quantity -= $quantity;
                $cartItem->save();
                if ($cartItem->quantity > 0) return true;
            }
            $cartItem->delete();
        }
        $this->resetCalculations();
        return $this;
    }
Removes an item from the cart or decreases its quantity.
Returns flag indicating if removal was successful.

@param mixed $item     Item to remove, can be an Store Item, a Model with ShopItemTrait or an array.
@param int   $quantity Item quantity to decrease. 0 if wanted item to be removed completly.

@return bool