I honestly am getting ready to do the swap. I have an older jrxp652 and thats why I picked up the gws receiver. The receiver in the 4in1 is removeable and the pins you see plugging into the gyro and esc are the throttle and rudder channels. Its just a plain ol 6ch receiver they mated up to the esc. In the 3in1 they have made them easily seperable.

One note..If you want to use an aftermarket esc of some sort all you need to do is tap into the throttle channel of the receiver while still allowing the receiver to plug into the gyro esc and y into the power for the seperate esc. Very simple if you are handy with a soldering iron, potentially very bad if you aren't. Be sure to tap only into the signal and ground of the receiver if your separate esc has an bec cirquit. the receiver will still get its power from the original gyro and esc.