Open the computer and turn it so that the screen faces you.

Pull the upper case off, lifting from the back, and working around the edges.

Use a spudger to loosen the casing if it sticks.

Once the casing is entirely free, lift it off of the computer.

The sound ribbon cable is very fragile. Be especially careful when disconnecting the cable from the logic board.

Disconnect both ends of the orange sound ribbon cable that crosses over the hard drive, removing tape as necessary.