My keyboard has a lot of buttons that doesnt work at all

@karamalbataineh sounds like you will need to replace the keyboard. Of course, there is always a chance that this is just a bad keyboard cable (check for corrosion and or it being loose). Here is the bad news. The keyboard is considered to be part of the top case. It is attached to the top case via plenty of plastic tabs.

You can try and break those tabs to remove the actual keyboard. Then you will have to find a way of attaching a new keyboard to the top case. IF the top case is not to thin, you can always use some very small screws and use those to attach the keyboard to the top case.

Workwise it is just more work since you will still have to remove the top case. Cost wise you may save 50% if you can find a way of attaching a replacement keyboard.

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