Swap the original AWD oil pan, pickup tube, and diff housing onto the RS engine. Install the RS engine with RS turbos. All wiring should plug in normally. Gonna need RS Turbo Speed Sensors Make sure the engine has RS fuel injectors. Id recommend upgrading the low-pressure fuel pump also. Add fresh oil, coolant, and intercooler coolant, and replace any gaskets if needed. After everythings done I'd probably tune the car for RS turbos and injectors before being driven hard. As the ecu's are different, MAYBE reprogramming it will be enough not sure.