Trying to add a scar onto a follower's facial texture

[RieFairy]

Okay, so I know the basics of making a follower and putting them into the game. I've done that a few times. Now I'm making a new one, but I came across a mod by Xenius: Scarface. I really like one of the scars in the mod, but since I'm making the follower with the Epic Elves custom race, I haven't been able to get the mod to load in the CK (at least I think that's the problem, I'm not sure.) So I've decided to try and just add the scar onto the follower's facial texture/Face Tint. The problem is, I don't even know where to begin. I'm willing to learn how to do so, and google searches have turned up names like Nifskope and the like, but I'm not sure if that's what I need.

 

I do have Photoshop and the DDS plugin required to open that file type, but how I would get the scar onto the follower's Face Tint is beyond me, with Photoshop or some other program (or even the CK if I could get it to work with the race somehow) and google hasn't been that helpful since I'm not quite sure what I'm looking for.

 

Anyone have any ideas?