Hi,
''The water causes corrosion and provides circuit paths for the electricity which were not in the laptop’s operating design and could damage the components. The corrosion starts immediately and is ongoing until it is completely cleaned away''
''First '''do not try to charge or to turn on your laptop''' and then '''remove the battery as soon as possible''' from the laptop'' to minimize any further damage.
Then you need to dis-assemble the laptop and clean ''all the affected parts'' using '''Isopropyl Alcohol 99%+''' (available at electronics parts stores) to remove all traces of corrosion and water. Do not use "rubbing alcohol" as in some cases this is only 70% IPA or less, can contain additives and is not as effective. If you do check the label to verify the amount of IPA. The higher the percentage of IPA the better.
Here is a link that describes the process. [[Electronics Water Damage]]
As always with electronics, especially surface mounted PCBs be gentle when handling and especially when brushing away the corrosion. You do not want to remove any components from the board. The ends of any flex cables and their connectors need to be cleaned as well
Hopefully after you have done all this the laptop ''might'' possibly work correctly again.
Here is a link to the ifixit [guide|25355] guide(s) for repairing your laptop that may help. If it is not that helpful, what is the full model number of the laptop?
Also with keyboards usually you can create more problems than what you have in trying to repair them. If the rest of the laptop seems OK then it may be easier to replace the keyboard rather than attempt to repair it.