Clicking on an Open position will give you details of that order. From here, you can Update or Close your order. If you change or set a Stop Loss (S/L) or Take Profit (T/P) on an open position you must simply click on the 'Update' button to confirm the changes. A confirmation screen should appear shortly after updating the order.
If you select a pending order from the trades area, you have the option to Update/Delete the pending order. You can change or adjust the open price, the Stop Loss (S/L) and the Take Profit (T/P), remember after making such changes to click on 'Update'. Again, a confirmation should appear shortly after . To Delete the order simply select the 'Delete' button.