A couple of points for you:
The Optimax chip is more of an "optimising" chip and should give better fuel consumption, the Tornado will release more performance and better drivability, and is the usual choice for Hotwire +8 owners .
You have to unbolt a couple of items from the top of the bulkhead before you can access the bolts which hold the ECU in place on the underside. The really big issue is getting the plug back into the unit without bending any of the pins . You have to be incredibly careful to do this successfully, as you are working upside down in the passenger footwell, and everything is a bit tight.
Good luck
