You get black textures because that layers (163, 164) are only available for male. You have to disable them using the value -1 (negative one). Once you disabled both of the clothing layers, you need to set the armor clothing layer (155) to the armor number, or whatever you want, you can use clothing from other armors too. Try the female character if you want to see how clothing layers work.
To open 3d models you can use the official tool from Microsoft called DXviewer. With that you open the models in .x format, and it loads the texture automatically if it is in the same directory. However, you have to know the exact name of the default texture.