How can i remove/add civ?

[Rising Sun]

Hi, i just downloaded this Earth18Civs and it is great but i think American should be removed so Europe Powers can go over there some day and see how they react to natives like the Aztecs and Incans.

So i had all civs named properly for example Elizabeth (English Empire) so it would be called English samn for all other Empires. Cant stand the name of leaders becuz they dont live more than 80+ years. Always will be replaced with lesser or unique leader in the furture.

Anyway i was trying to remove the American off the map on the Eastern Northern America thru World Builder ingame. So when i remove all units included the settler it seem to be replaced automatically every time i saved my work. So how can i permently remove that civ thru World Builder ingame?

**Nevermind i figure it out thru notepad editing**