These four screws are tricky to deal with. They are well recessed and hard to spot at first. A magnetised screwdriver is a prerequisite. Another way is to glue the screw heads to the screwdriver with some very weak glue, and let it almost set before trying to locate the screws back into their holes whilst re-assembling. I lost one screw somewhere inside the computer! It is alright with 3 but I hope it doesn't touch something vulnerable on the circuit board.
This is tricky and took some time and patience. It is best to have some foil tape handy because the EMF shield tears easily. Likewise when reinstalling the screen and EMF shield, it helps to have a partner who can stop the foil to the side of the screen from getting folded under the screen when you lower it back into position, ready to tape it back onto the edge of the screen.