Remove all screws from the back casing. (4X 18mm, 4X 10mm, 6X 6mm)

Press your finger in the hole next to the hard drive to lift the key board. You may need an iFixit opening tool and work your way around the edges of the keyboard to get it fully lifted.

Move slowly as the power cable at the front of the keyboard is still attached to the motherboard as well as the ribbon cables.