You can post your ECU to Autolusso and they'll do it for £150 + postage.
Changing the metal-flapped manifold for a flapless CF2 will be complicated as the CF4 ECU expects to see the swirl flap actuator and will throw an error if it doesn't, because there isn't one.
If you de-flap your existing manifold there's no problem, because you leave the actuator in place and operational although the rack and pinion and swirl valves have been removed. The ECU doesn't know nor care that it's just rotating the actuator spindle.