How do I change the CFG file?

Scroll down a little and the instructions you want are there.

https://forum.flyawaysimulation.com/forum/topic/33358/how-to-install-aircraft-in-fsx/

You may find this article interesting:
https://flyawaysimulation.com/news/4795/

Thanks. It sort of helps. Windows 10 won't let me open it to begin with. I have to search the chrome shop for a program that will let me. I'll go explore.

Windows 10 won't let you open FSX? What error messages are you getting? Any at all?

Try this.

https://forum.flyawaysimulation.com/forum/topic/36717/help-cannot-make-changes-to-aircraftcfg-file/

No I can open FSX no problem and it runs great etc. Windows 10 won't let me open the CFG folder or any CFG Folder. It says I require an Extension App to open the folder. The App store is not helpful as such. I tried their recommendations and so far no joy. It's not a big deal, as I fly from the inside, it was just I would have liked either the Ansett or Qantas livery on the Electra, as it is the Aircraft I fly the most, 99% of the time. It's not that big of a deal.
It took me longer to figure out how to get FSX to work on windows 10 without crashing in the first place. It works better than with XP or 7 etc, and I get awesome frame rates in Max detail.. It was more about icing on the cake, Icing I can't see because I'm in the Cockpit. I'll keep working at it till I find a solution. I just wondered if anyone else had encountered this and could help me shortcut it a bit.

How to:

This will be also interesting to read:
https://flyawaysimulation.com/news/3806/