HOLY SHIT I FIGURED IT OUT!!!!!!!!!!!
Well, OK, I had a lot of help from @deedee-sims for clueing me in to use export/import instead of extract/replace and from @zena-dew-drop, who did some lighting up of already-existing hood deco buildings, so I was able to pick apart one of their files and figure out what I needed to do to make it all work. So, huge thanks to both those people. :)
Now to see about the textures, maybe res them up a bit to see if that lessens the blurriness in closer-ups and in lot view without having to create completely new textures....Which I don't have time to fiddle with right now because I gotta get my butt in bed. But...VERY HAPPY! :D
And hopefully I can now apply this principle to another form of hood deco... *fingers crossed*
