Working with NPC Models

[MrRangaSir]

Hi all,

 

Recently I've decided to give some new race mods a go and found some real quality characters can be made. The only problem is that I can only use one of these at a time when setting up screenshots. This leaves me with a question for the community. How could I go about replacing NPCs with the models from these custom races, while keeping their classification as one of the base-game's races? Is it even possible?

 

Thanks for your time :)