Remove the two screws holding down the keyboard trim.

Remove the two screws securing the left speaker, then move it to the side.

Remove the five screws holding down the shielding. Note that the long screws used here aren't as long as the screws used to hold down the keyboard etc., so keep them separate from those.

Remove the two remaining screws securing the heatsink, and lift the heatsink from the rest of the system, and you are done removing parts!