This is a short manual how to leave only the races you want from this huge mod. The first you need to find this mod in workshop folder. You need to go to the location ... Steam\steamapps\workshop\content\281990\814332008 and find a zip file. Later you need to unpack it and go to the ... common\species_classes ... there is a file per mod section. You just need to add # before the name of the race you do not want and save it. I here you go, the race you do not want is hidden. This manual is maybe more important for those who use patch to randomise/spawn races as base mod do not force spawning of any race.