Step 13
Once the front and sides of the lower case are free, turn the computer so that the back is facing you and pull the lower case up and toward you until the back tabs pop free (it may be helpful to jiggle the case up and down).
Step 14
Remove the small greasy springs with white plastic caps from either side of the battery contacts.
Step 15 — Bottom Shield
Remove the following 10 screws from the bottom shield:
Six 3 mm Phillips
Three 7.5 mm Phillips
One 14 mm Phillips