You need to be sure you want to disconnect this trade by FIX, and that both you and the broker are aware of this change. If the broker does not know it and you disconnect it, the broker will continue operating.
Historical orders can be setup as Manual with NO problems.
1. Select a transaction from the blotter.
2. Right click mouse.
4. Set FIX Orders to Manual.
This will set your order to manual and allow you to change values such as price, filled Qty…