Installing MacBook Core Duo Battery: Step 1 Use a coin to rotate the battery-locking screw 90 degrees clockwise. /Guide/Repair/MacBook-Core-Duo-Battery/278/all#s1066 Installing MacBook Core Duo Battery: Step 2 Lift the battery out of the computer. /Guide/Repair/MacBook-Core-Duo-Battery/278/all#s1067