Now, with plastic cover removed, simply pull keyboard upwards. Not too hard, since it is still connected to the motherboard.

There is ZIF (Zero Insertion Force) socket. Use some wooden pick or thin plastic tool to open the connector by pulling out that brown part by either of sides.

With connector open, keyboard cable should be free to pull out. Do not use force, as these are delicate parts.

Connecting cable back is a bit tricky - make sure cable is seated properly and tab pushed in and secured.