You can change the quantity and price of an order in the same way using both DOMTrader and the DOM area on Order Ticket.
To change the quantity
1. Click the order in the Buy or Sell column.
2. Type a new quantity value or click a quantity button.
3. ENTER.
To change the price
1. Click the order in the Buy or Sell column.
2. Drag and drop it at a new price.
3. If prompted to confirm, click OK to apply the change.