Next, undo 2 screws (in red) holding the keyboard in place. You'll notice that there is a small keyboard icon next to them.

Put the hard drive back into the slot, ensuring that the the blue tabs on the corners of the hard drive are snug against the case and that the wire on the bottom right doesn't kink or get damaged.

The laptop will need to be turned over at this point. Support the hard drive as you turn the laptop right-side-up and lift the screen up.