Posts from the models won't export. Auto-translated

I apologize for posting in this thread: I just wanted to quickly send a message while I still have an internet connection, rather than searching for the right thread. Besides, this issue is also discussed here.

I would like to understand what is meant by "recoloring" units. I've noticed that some mods have excellently recolored creatures, and I'm trying to do the same, but I can't seem to get it right. I change the model and textures of a Death Knight to that of a Paladin, and as a result, there's some kind of mess on the horse with a smeared helmet and no eyes. I don't need a Paladin to be there; I just want the Death Knight to have armor of the same color. Also, I can only replace the textures of a specific part of the monster, for example, the entire body at once, but I can't recolor the sword separately.
What am I doing wrong? Do I need to create my own textures and then link to them? Or should I use existing ones? For example, if I recolor a dragon, the shine in its eyes always disappears. I hope for an answer.

1) So, I need to recolor using standard editors, not within the map editor itself? I couldn't figure out how to work with the DDS file there.

2) No, I'm just interested in how to recolor for now. Creating my own creature is just a plan.

3) Yes, there is, but the problem is that the Death Knight has one material for the horse, shield, and sword.

I have a small question:
So, I extracted a screenshot, recolored it, saved it as a TGA file, and put it in the map in UI/H5A2/Creatures/NecropolisSecondUpg/name.tga; and also in model/.../.../name.tga.
Then, I opened the map with WinRAR, found the file in model: something like DeathKnight_Coat.xdb. Inside, there are Scr_name and Dest_Name. In the first one, I wrote a long path through UI, and in the second one, I wrote name.tga directly, since it's in the same folder.
I opened the editor, checked, everything matches, the links appeared. I decided to check how it looks, selected it, and the editor crashed. What did I do wrong?

Yeah, I'll try it now. So, they use TGA for regular textures and DDS for 3D coatings?

Added 41 minutes later
Okay, it worked. The only thing is: for some reason, the horse has become a bit whiter, and a white background has appeared around the chains, which I definitely didn't create.

You can export it to dds using the editor.