SniperHF, you are awesome!
After reading through your comments this is what I ended up being able to do:
1) get Demonata's files
here2) open up The Divinity Editor and make a new module (SneakingAnimationMod) with dependency Main, module Main selected
3) open Modding->Module Settings and fill in info; set startup level to Character Creation and menu level to Menuscreen_Cyseal; save (note: if you do not set a startup level your game will probably hang on creation)
4) open Resource Manager (create and view resources icon)
5) using the leftmost pane, click on mod's folder (SneakingAnimationMod_960a8da4-3d61-4400-912c-1b853e193b0d in my case) and then click on the little package icon with a green + on it; name the package (I called mine Models, but I think it's irrelevant) and hit OK
6) using the leftmost pane, click on the Main folder
7) type in "model sneak" in the Filters text box
8) for each of the four sneak models listed (the ones with the teapot icons), right click on the model and select Copy to my module..., make sure the mod's resource package is selected (again, mine is Models) and then hit OK
9) now minimize the editor and go copy Demonata's four .GR2 files to the mod's Assets\Effects\Effects_Models folder; you will need to create the necessary folders; I ended up copying the .GR2 files here:
...\Data\Public\SneakingAnimationMod_d5c39eb7-ab48-40ab-90bd-e3e10e8e3616\Assets\Effects\Effects_Models
10) using
Norbyte's LS Tools open up the mod's ...\Data\Public\SneakingAnimationMod_02c0493b-852a-4811-9194-1222d1c92097\Content\[PAK]_Models\Models.lsb file
11) Under ResourceBank->VisualBank there are four Resources listed; click on each one and for the SourceFile, change ...\Main\... to point to your mod's folder instead; for example:
Public/SneakingAnimationMod_02c0493b-852a-4811-9194-1222d1c92097/Assets/Effects/Effects_Models/FX_Model_SneakRock_Char_A.GR2
12) File->Save ... back to your mod's Content\[PAK]_Models\Models.lsb file and overwrite/replace
13) back in The Divinity Editor click on the Save all icon
14) select Modding->Publish module and then click on Publish
Now activate the mod in-game and then blam! thank you Demonata08 and SniperHF!!! I KNEW it was something trivial. This is how easy it's supposed to be, you know? Please correct me if I'm just missing something here, but I'm amazed that documentation on the really trivial things like this is lacking. Bleh.
IMPORTANT NOTE:
I did do this one time completely in the editor by opening up the SideBar and changing the source files for each of my mod's models to point to the models in my mod's Assets\Effects\Effects_Models folder (as per SniperHF above). This resulted in the same visual artifacts he experienced. I believe it's somehow related to the skull that is in Demonata08's files? If you notice in game, it's just texturing a giant skull beneath the character's feet with a bush, rock, etc.
When I use LS Tools to change the source file this doesn't happen. /shrug
I'll post an edit if I figure out a way to avoid this happening using just the editor.
Thanks again SO much SniperHF for help in figuring this stuff out. I appreciate you taking the time to share.
Take care!