I'm a bit confused. There's only one texture for Shadowmere and it's only 256x256 px. There's no normal map, glow map or anything else. The only other Shadowmere texture is for the saddle. Help please!
EDIT: I think I figured it out and I'm not sure I can do any specific changes to Shadowmere without the CK. It seems that there's a special overlay texture applied to Shadowmere's model so if I edit his base texture (probably the black horse one) it will change the regular black horse as well... Major bummer.