Latch the back end of the upper plastic cover over the plastic tabs at the back of the machine. (photo 1)

Gently rotate the front of the lid down and press it into place, making sure that the posts on the upper steamer lid align with the holes on the lid. (photo 2)

You should be able to slightly rotate the upper locking handles and feel resistance as they engage the steamer head below them.

After pressing all the locking plastic tabs into place around the top of the machine lid, you should be able to open and close the machine lid using the locking handles.