Please do some research before you start asking questions. There are plenty of topics on this, and google will tell you quickly enough too.
Because I'm in a good mood I'll give you a very brief explanation,
Now the transmitter tells the receiver to power the motor, you have to get rid of the transmitter and receiver, and replace the receiver by a microcontroller.
Then program the microcontroller to power your motors...
But if you would have committed yourself for 2 minutes you would have found this explanation or probably a better one.
