Ensure that the cables are bent downwards, but not at an extreme. Slot in the cables into the gap between the trackpad and the metal backframe.

Go around the keyboard clipping it in, then reinstalling the screws. reinstall the keyboard shroud carefully by clipping it into place, ensuring it is in the correct direction

Turn the machine back over, and then reinsert the cables to the corresponding connectors, and carefully push the black tabs down