To change the com port used by InteractX drivers on a runtime system without the development software and the need to re-download the application to the HMI, you need to be able to get to the Windows desktop.
If you have a way to exit the application, you can exit back to the desktop and look for the Com Server icon in the system tray. It looks like a little hand holding a box and is close to the system clock at the bottom right of the screen.
If you have no way to exit or if when you exit the Com Server "Hand symbol" does not show up in the system tray, you will need to attach a keyboard. Once the keyboard is attached and the application is running, hit the "Ctrl" and "Esc" keys together or the "Windows Key" if it has one. The Windows system tray should become visible at the bottom of the screen. Your application will still be running above the Windows system tray bar at the bottom of the screen.
Clicking on the Com server icon will open a configuration screen with the drivers shown in a tree structure at the top left of the window that opens.
Select the channel "Top level branch" and in the properties you can change the com port it references. If you are using both ports, it will be necessary to set one to a non-existent (com4) port initially since two drivers can not be assigned the same port number.
Once your driver or drivers are pointing at the correct ports, you need to click "File" at the top of the page then "Save" to make your changes permanent.
For the changes to become active, you will need to restart Windows to have the Com port changes recognized by your application.