The smaller of the two cables is for the touchpad. Lift the catch on its connector in order to slide it out.

The larger cable is for the key matrix. Just pull it out from the connector (friction fit).

This is as far as you can easily disassemble the keyboard. To go further requires removing 12 screws and 35 plastic rivets. This is not recommended.

To clean the keyboard of liquid, I suggest holding it over a sink with the touchpad side up, then spraying plenty of isopropyl alcohol from the back, avoiding the touch-pad area (you may wish to mask it off). Let dry completely before reassembling.

If keys still do not function after cleaning, then it is possible that traces on the key matrix have become corroded. This is not repairable, since the key matrix is a sealed unit. It consists of 3 layers of plastic that are sealed together. Unfortunately, it is not 100% sealed to prevent entry of liquids.