When reassembling, keep the unit upside down and slide the bottom cover back into place hinges first.

It is a little fiddly getting the clips near the hinges and battery compartment seated.

Once the hinge area is close to being tight enough to push the clips back together, run your fingers down the sides by the keyboard to clip the sides and front.

Turn the unit upright open the lid and slide your fingers along the edge under the display and all the way around the edge to be sure all of the clips are back in place.

Reinstall the optical drive.

Turn the unit upside down again.

Replace the screws that will be hidden under the black covers by the hinges.

Replace the black covers by the hinges and then all of the rest of the screws. Don't forget the cover stickers for the two hidden screws.