to all you experienced tankers

I have some experience with RC cars and trucks.
All the RC cars that I have you can just plug your own Rx straight into the Motor Control Unit
what do you have to do to be able to use your own 2.4Ghz Tx and Rx on a Heng Long board ?
As the HL board seems to incorporate the Rx in it, rather than it being a separate function.
If someone else has answered this question I'd be super grateful if you could direct me to that post
thanks for you help