Read the manual SPM20320.
http://www.spektrumrc.com/ProdInfo/F...l_SPM20320.pdf

To bind the receiver to the transmitter
1. Make sure the transmitter and receiver are turned off.
2. With the receiver off, insert the bind plug into the BIND port on the receiver.
3. Power the receiver through any port. The green LED will flash continuously, indicating the receiver is in bind mode.
4. Hold down on the SCROLL and CHANNEL buttons while turning on the transmitter.
To enter System Mode, press the SCROLL button until “BND” appears on the screen.
5. With the steering wheel and the throttle trigger in their desired failsafe positions, press the INCREASE and DECREASE buttons at the same time to enter bind mode. “BND” will flash when in bind mode.
6. After several seconds the LED on the receiver will quit flashing and remain solid, indicating that the binding process was successful. Once binding is complete, the system will automatically connect.
7. Once the bind process is complete and before power is cycled on the receiver, remove the bind plug from the receiver and store it in a convenient place. Failure to remove the bind plug will result in the receiver going back into bind mode.