Remove the following 10 screws securing the lower case to the Air: Six 2.8 mm Phillips screws. Two 3.8 mm Phillips screws. Two 5.4 mm Phillips screws. /Guide/Installing-MacBook-Air-Models-A1237-and-A1304-Lower-Case/847/all#s4617 Slightly lift the lower case near the vents and push it toward the rear of the computer to free the mounting tabs. /Guide/Installing-MacBook-Air-Models-A1237-and-A1304-Lower-Case/847/all#s4618 Slightly lift the lower case near the vents and push it toward the rear of the computer to free the mounting tabs. /Guide/Installing-MacBook-Air-Models-A1237-and-A1304-Lower-Case/847/all#s4618