Go to your game's Data > English folder and search for the TechTree.xml
In that file you'll find many different technologies, use the Ctrl-F tion to find the tech you wish to remove and simply delete it. Note that removing a tech might have a huge effect on the game. Techs such as the Universal Translator are vital to the rest of the game, while others may be less important. Each tech is there for a reason, some unlock Improvements and some give you bonuses that otherwise you wouldn't get. You should backup all your files before removing said tech, and choose wisely what you are going to delete.
Alternatively, you can make a mod with all the techs, without this one so you don't have to delete any core files. Hope I helped.
