The armature should be pieced together as one component. See photos in previous step for how it will look when correctly pieced together.

The armature attaches in two locations. At the bottom edge, and at the top edge. You need to install the armature from the bottom edge first. There are tiny metal hooks toward the centre of the bottom edge, and there are two tiny hooks at each corner along the top edge.

You need to slide the bottom edge of the armature under the hooks so that the two holes in the armature get hooked onto the keyboard.

Then drop the top edge down onto the keyboard, and gently push the top left and top right corners so they click onto the small metal hooks in those locations.

The armature should now be reattached. Test it to ensure it's attached.