Have a look at the recent update by @David-H here.
I found it impossible to unplug the required connector with the OEM controller in-situ, and so resorted to removing the 10mm AF mounting frame bolts. With that loose, it was just possible to wriggle the module out, rotate it to access the securing clip, slide a thin jewellers screwdriver that I had ground down earlier to resemble a very thin chisel to release the locking tab and finally pull the offending connector out. After that, everything was easy-peasey.
I hope this proves to be useful.
Laurie