With the case closed, place the Unibody top-side down on a flat surface. Depress the grooved side of the access door release latch enough to grab the free end. Lift the release latch until it is vertical. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4447 With the case closed, place the Unibody top-side down on a flat surface. Depress the grooved side of the access door release latch enough to grab the free end. Lift the release latch until it is vertical. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4447 The access door should now be raised enough to lift it up and out of the Unibody. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4448 Be sure the access door release latch is vertical before proceeding. Grab the translucent plastic tab and pull the battery up and out of the Unibody. If the latch is depressed it will lock the battery in place. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4449 Remove the following eight screws securing the lower case to the chassis: One 5.4 mm Phillips screw. Three 14 mm Phillips screws. Four 3.5 mm Phillips screws. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4453 Using both hands, lift and remove the lower case off the upper case. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4454 Remove the following 5 screws securing the mid wall to the upper case: Three 10.5 mm Phillips screws. Two 3.7 mm Phillips screws. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4469 Lift the mid wall out of the upper case. /Guide/Installing-MacBook-Pro-15-Inch-Unibody-Late-2008-and-Early-2009-Mid-Wall/825/all#s4470