Thanks. I'll start off by saying, I am just starting to learn the basics and don't know much

I am making an altered melee map, its not really very different from standard melee, but it has some cool extras.
I wanted to add a new race to my map (not a lot of races, just 1 or maybe 2) so I figured I would start with Naga. I've been looking at different Custom Races people have shared, there is a Draeni somebody posted recently that I am thinking about importing into my map, but I'm still learning a lot.
I found a cool map that has a Naga Race using Undead buildings, like they haunt the gold mine and have blight, but theres cool textures added like instead of blight it has shallow water. I am trying to read any tutorials I can, I know about Warcraft 3 Viewer but don't know what its for other than importing images (I did use it for a loading screen). I know the blight texture is called "Lords_Blight.Blp" and I was able to export it from a map I downloaded into my map, and I know I had to change the path to custom which I did, but it doesn't show up and I don't know how to set it so the naga buildings use shallow water instead of dark terrain.
I also have a few other problems, like the builders texture is not appearing even though I imported it.... but now I know I am rambling on and asking too many questions lol.
Back to the point of my OP, the Naga Race i am currently trying to setup, works as a 5th race, so players have a dialogue menu at the start asking if they would like to switch to naga or play default races. If a player selects Naga, then I have triggers replacing their units with Undead in order to have the starting units = 3 workers and 1 ghoul because thats how this Naga is setup... I mean it doesn't have to be that way but I thought it was cool.
Sorry for writing so much but, the point is that I can not replace or remove the Undead Haunted Goldmine correctly, and add in a new "Naga Goldmine" which the naga goldmine is basically the exact same thing as a Haunted Goldmine just with a new texture. It doubles up and creates 2 overlapping goldmines (one with the naga building, one without) allowing players to use both