Prestige buildings, imperial palaces and so on

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Hey guys
My question is how to remove or change the conditions for them?
I guess I'm gonna need a step by step description. I've downloaded the DBeditor and just changed the data from the cells into what I wanted but it had no consequences on the game whatsoever, and, uhm, basically, I have no idea what I'm doing.
Please, help, anything will be greatly appreciated!

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I'm more interested in the way to make changes take effect than in the tables themselves (at least I could find the necessary ones).