You should not have to replace the whole upper case. You can disassemble the keyboard by taking apart Logic Board & Superdrive. Disconnect the battery. Once the LB and Superdrive are out, pull out the Backlit Black layer. Underneath the black layer there is transparent layer and underneath that you will see white layer. Pull them out. Once you pull them all out, you gonna see the real Keyboard been there secured by 2 large black stews and small silver 56 screws. Large 2 screws secure the power button and the small screws secure the keyboard. Use phillips 000 screw driver and take them all out. Your keyboard will simply be out. Then replace with the new matching part and place the layer out if the new one doesn't come. Even the new one has mentioned layers, you got to separate them to while placing on the top case. It is a fun replacement. If you want a keyboard replacement video, I can send you my own raw video about it.
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