Thought I'd just reply here after doing this today. Everything is so easy....And then you have to line the pins up! I've never swore so much in my life! What an absolute pain in the grass! I took the vent grill off above the controller for more access and still couldn't do it! In the the end I had my wife with her smaller hands in there and she managed to line them up after about 30 mins! So anyway all done and it's still not solved the irregular fan speed and air con not working! Oh well. Blower resistor and a trip to the ac shop!
Thanks for the help on this thread though. It did help a lot.
Ed