Thanks for this - seems like too much work for me. I remember when I had to do something similar to use special hairs and armor textures (not just the simple mod that uses the save editor) for Shepard in ME:3. It was such a pain to do I stopped bothering, lol.
Bioware has confirmed that they are working on "no PJ's." Hopefully they'll do something about it soon.
Was this easy to do? I read over the steps and sounded... complicated. 
I thought it was gonna be complicated, too, and it looks like it is if you're actually trying to cheat, like having unlimited supply of this and that in the merchant vendor, etc.
But if all you want to do is toggle off Skyhold outfit (as well as the HUD/interface!) it couldn't be easier. It took me 5 minutes and I'm the type of person who can't be bothered to mod anything more involved than just clicking a few buttons in Nexus Mod Mangager.
1. Load Dragon Age Inquisition game.
2. Open Cheat Engine 6.4 (64-bit version) (download here: http://cheatengine.org/downloads.php)
3. Open cheat table (download the .CT in this post) with CE. (Menu > File > Load) Hit yes when asked if you want to run LUA.
^ just download the "cheat table" thing "DragonAgeInquisition.patch2hotfix.CT" at the bottom of the forum post
4. Open DragonAgeInquisition.exe process with CE. (Menu > File > Open Process > Select "DragonAgeInquisition.exe" > Open)
^"DragonAgeInquisition.exe" is literally right there in the list that opens up
5. Check the box next to the scripts (red) you want to activate in the bottom panel.
Right there, "Toggle Skyholdoutfit" is listed, and all you have to do is check the box. If you're in Skyhold while doing this, just open up Inventory, and reapply your armor, and thats it. I also like to use Toggle HUD. I gave it a hot key, and it's a easier way for me to hide the interface rather than using the command console.