Change nif/dds of a vanilla npc

[peppefarina]

hey guys  

I have a basic understanding of how to change body meshes for a standalone npc

which comes with an esp and relative meshes/texture/facegendata folders,

but how do i change the meshes of a vanilla npc?  

 

I've looked around, the only answer I find is to make a custom race?

There are other ways? 

I know there are some mods that use various body type to change several npc, but that's not what i'm looking for.

 

I need the quickest/simplest way to change the .nif/.dds of a vanilla npc. and only his/hers.

 

thanks guys.