Pending and filled orders may be easily modified by following these steps:
1. Find the "Orders" window on the your platform and right click the order you would like to modify.
2. Select "Modify Order" from the dropdown box.
3. Modify your trade in the "Modify Order" dialog box.
4. Click "Ok" at the bottom of the dialog box.
Please note that you can only change the lot size of an order that is pending, lot sizes on active orders are permanent once the order has been filled. You can find out whether a trade is pending or filled by referring to the "Status" column of your "Orders" window.