The datasheet for the servos you have should tell you which pins are for what. Most of the wire colors vary from one company to another (one of the things I hate about the RC industry is nothing is even close to standard), with some even varying the pin order on the connector. Although I have never seen a servo with two black and one red wire, I would assume there is a positive, negative and signal wire. You just need to figure out which is which, and when you do you can pop the pins out of the connector(gently pry up the plastic tab holding each pin in place and slide it out) and put them in the order you need.