Orders can be adjusted on the trading chart and via the Positions panel.
To change the limit/trigger price of an order, drag the order on the price chart to the desired limit/trigger price. Once the order has been amended, you'll receive a notification detailing the change.
To adjust either the limit/trigger price or the quantity of an order, you can go to the Active Orders tab of the Positions panel and click on the pencil icon to make a change. To confirm a change, click on the green tick. To cancel a change, click on the red X.