1. Turn off your laptop, and disconnect the power cord.
2. Dry your keyboard, under the sun or other source of heat you can find (of course not so hot that it is likely to damage your laptop) You can even use hair dryer.
3. Keep the lid open and stop using your laptop for 2 or 3 days (trust me keyboard need a lot of time to dry)
4. If you have a lot of free time, remove your keyboard button and wipe it dry. (I don't have tutorial for this)
Still whatever you do, you have to let the keyboard dry, or it may not function at all after that and worst case ever it keep on pressing one button non-stop. This may due to short circuit in your keyboard. If this happen, you can still remove your keyboard button but there is no guarantee that it will function again.
Well in my case, it happen on my study week and of course I can't let my days passed by without studying ( I am fully dependent on my laptop for the notes). Besides all the advices I found on the internet I still kept using my laptop. So, in the end 13 buttons cannot be used, even after I do this...
Before I remove my keyboard button
After...
Very dirty! With all the debris and dust..
So now I'm using USB keyboard I bought with its sole purpose is for playing games, now, it become compulsory whenever I want to use my laptop.
P/s: Please value your laptop. It is not cheap. (T_T)