It took me an hour first time. But then, if you know what are you doing it only takes 5-10 minutes if so...Here's some tips:
First remove the passengers side kick panel. Then remove the glove box. Using a 1O mm socket remove the one nut holding the ECU's wiring harness to the ECU. A white plastic bracket will be holding the ECU in place. Remove the one screw holding the ECU in place. Pull the ECU down and out. You are good to go!