I did do that, however, if I open the folder of one of the DLC prefabs, all that is in it are pmg, pmd and pmc files, none are dds files, unlike in the standard ingame prefabs, which also had a dds so you can reskin parts of the building.
I think All of the dds files of the prefabs are in the Materials folder in the Base.scs.", try finding what dds files you need. (I'd find texture files by using Blender w/ 50k's plugin, I just Import the .pmg[3D files] from prefab folder to Blender and Go to the Texture Tab and find the Textures location). I suggest that if you try opening 3d files from the Prefab folder to Blender you can have less time in finding a particular texture. But if you don't know or having difficulty in using Blender, just tell me what texture you can't/hardly find.
If they're not in the base.scs then there should be a different archive in the same place with the corresponding DLC name, should imagine it's in there! I've not bought the scandi DLC so afraid I can't help you any more than that :P