1 - 4 hours
I added a SSD drive to it and replace the optical drive with a new one.
It went well except i forgot to remove the ir sensor before i pulled out the logic board so it was little bit tricky to put it back inside :)
An unknown cable unplug itself when i put back the logic board. I was lucky enough to look at the tutorial pictures to know where it was plugged before (the one near the optical drive fan slot).
Be careful to not unplug the cable in the picture when you put back the logic board because it can get stuck easily in the screw hole of the logic board.