When installing new keyboard, carefully thread metal tabs through the holes. They bend easily, I used flat metal spudger to slide in each of the tabs.When you screw everything in and all cables are connected, don't forget to bend these tabs so they hold top of the keyboard more securely.
On mine 3 of the screws were covered by black film. Remove it and then replace it when you done. It helps to stop liquid and dirt from seeping in.