Just installed the green filters over the weekend. As many had mentioned in this thread, it is pretty simple , even for me who have never done any work harder than this one. Here are few pictures which were taken during the work. I hope it will be useful to those who like to have visual of the procedure.
Engine bay with the front plastic cover already removed and the back cover is loosed. There is still a zip tie attaching a hose with the back over which need to be cut.
As shown below, it is a black zip tie attach the back cover to a hose
Engine bay without the covers/airbox, it is pretty amazing to see that a big heart is fitted into a rather small car!
few screws later, you have the airbox removed, lots of crap in it!!!
same goes with the other side!
reverse the order and put everything back into the car, as well as new zip tie (in white)
Done in 30 minutes, time to enjoy the new green filter. I also gave it a quick wash to the car at 3 degree C, that was cold!
The engine is definitely more lively and the car has better response to the throttle.

I will see if the milage will improve in the next few weeks.
Smart module is on it's way and will be the next item to put in, just in time for the summer!!