On the nearest part of the connectors are slides that lock in position to hold them in place.
Slide them back out by levering them towards the back of the car with a screwdriver.
As the slide is pushed back it will unlatch and lift the plug off of the ECU.
If you do the top one first it gives you better access to the lower one.
The ECU is screwed into the side of the airbox. The screws are in the same positions as the pockets on a pool
table so just take the screws out and the ECU will be free to be removed from the car.