Repairing/adding drivers in SBEC/2

I am looking for advice on changing the MOSFET drivers under the heat sinks of SBEC 1 +2.
I am studying the SBEC2 V6 to better understand how we can adapt it for use as a Turbo L4 ECU controller. I have reversed engineered the critical circuits and so far so good.
Has anyone changed the injector MOSFET driver chips?
It appears the centre heatsink under the fins needs to be removed for the centre unit to access all the drivers on the inside (8). The drivers are thermally connected to the heatsink via a silicone thermal pad.