Opening it up at this point will not help. It does not give you any further access to the keyboard. It is sealed with a metal plate from the backside.
The best way to try to clean up the undelightful spill is with repeated baths in warm distilled water in an ultrasonic cleaner. The cleaner helps get the gunk out with the water acting as the solvent.
Use three passes, at least an hour each in the cleaner with fresh distilled water each time, do not use anything but distilled. Shake out all the excess water, and let the calc dry out overnight between baths. Then dry at elevated temp (120° f) for 24 hours after the final rinse.
You may not need the ultrasonic assistance, since the spill is fresh, so the sooner you soak it in distilled water, the better the chance of success. You should try warming the water in a microwave to 105-115° f or so and immerse in a very clean glass pan. Soak for at least an hour each time.
Of course, don't forget to take the batteries out first.