Save the tech tree to this location: C:/Program Files/Stardock Games/GC2/Twilight/Data/English/TechTrees. That will put it in the game, but it miiiiiiiiight get you a cheat flag if you play on the metaverse. To eliminate this problem, go to C:/Program Files/Stardock Games/GC2/Twilight in the standard windows window, and make a new folder called "mods". Start the game, go to the options window, and check "use mods". Click "Choose", click "default", then quit the game. Put the tech in C:\Program Files\Stardock Games\GalCiv2\Twilight\Mods\Default\Data\TechTrees. Restart the game, and it will be there.