rane_nbg is correct up there.
But for future reference that is not a model its a texture/skin(better call it a texture)
To install follow theese rules.
1.) Locate your lfs directory. All paths from now on will be relative to the lfs folder.
2.) Locate the data/dds/ directory.
3.) Locate the files that you want to replace and back them up.
4.) Drag and drop your textures inside the data/dds/ folder and replace all
That should do it.
Next time you post for help be a bit more precise with what you need help with. We want to help but we can not read minds.
Dont be "lazy"

The more information you give us the easier it is for us to help you.