The easiest way to win with a specific country or person is to go into "Scenarios" and select "Lightning Round". Set the difficulty to "Chieftain" and select the person you need to win it with. Then, simply concentrate on upgrading Tech. You only need 24 Tech so it will be fast. Pick the Techs that take the least amount of time to research. Try to avoid wars with the other nations, but do not give Tech to someone if it will give them the lead. By doing this, it should not take very long to win.