[Andrés]

You should have no problem adding them to the main installation of the game (you can allways put them in a mod folder in case you want to disable all of them at once)

Istalling races is simple.

Most files should be extracted to the following dir:
SE4dir/pictures/races/racename/

.emp files to
SE4dir/Empires

and design names file to
SE4dir/Dsgnname

where of course "SE4dir" is the directory where you have the game installed (or the mod directory) and "racename" the beggining of the name of most files (e.g racename_Portrait_Escort.bmp)

I don't recall exacly the format of the races in NASY, that is if there's directory information stored in the zips.

If there is, you just have to extract to SE4dir mantaining dir structure, if not copy manually the files to their apropiate dirs.

I hope this helps.