The post above yours says how
You wire EITHER the green OR the white to a signal pin (via pwm connector) to a digital input on the RC. That's all you have to do...really! Well aside from the 12v supply which you've already done. What's really cool, though, is you don't even have to have the signal connected to see if your photosensor is working correctly. The red LED will turn on and off according to whether it is switching on or off. We used BOTH sensors: the two wire one is the source and the 4 wire one is the receiver. We mounted them right next to each other to measure shooter RPM (with a white spot to reflect the IR off of). Just connecting the 12v supply got them working (LED on/off as the wheel rotates). Of course your RC needs the signal in order for your program to do anything with the information, but it's still nice for troubleshooting (using the red LED that is).