It depends on the software on the xcal. If it is the latest software, when you go to load the custom tune to your truck, it will ask you about "Enter Opt Param". If you click yes, you can adjust various things (Just scroll up or down to view what you can change). Then hit save and it will load the tune with your changes.
BTW...You can only load files that your dealer sends you.
If you don't mind me asking, who was your dealer?