How to Use Different Races ?

[Power Man]

I have just downloaded several Star Trek races from the New age Shipyards.
I would like start a new game with my current race and some of them.

I do not recall seeing any information on how to add these races to the standard SE4 Gold game.

Can I mix these new races and empires with the old races?

Do I have to use a Mod? I rather keep my original SE4 files clean.

Where do I extract and copy the new Race files to.

What settings do I have to change?

If there is a place with this info, where is it?

My Nephew rally wants to play the Borg !