Hi @geekyguy ,
After this amount of time I don’t know if it is even able to be salvaged, but I suppose that you can only try.
First do not try to charge or to turn on your laptop and then remove the battery as soon as possible to prevent more damage from occurring. Even if the laptop is off, there is still power available at various points on the motherboard. The laptop’s power button is not a power isolating switch. Think of the laptop as being in an extremely low power state when it is off rather than being off and disconnected from any power source.
Then you need to completely disassemble the laptop and clean all the affected parts using Isopropyl Alcohol 99%+ (available from electronics parts stores) to remove all traces of corrosion. Do not use "rubbing alcohol" as in some cases this is <70% IPA, can contain additives and is not as effective. If you do have to use it, check the label to verify the amount of IPA. The higher the concentration (%) of IPA the better.
Here is a link that describes the process. Electronics Water Damage
As always with electronics, especially surface mounted pcb be gentle when handling and especially when brushing away the corrosion. You do not want to remove any components from the boards. You will also have to remove any shields that may be covering some components as the water may have got in under them and there is corrosion there as well. Also disconnect any flex cables and clean the ends of the cable as well as the connectors that they were plugged into.
Most probably you will also have to replace the battery.
Water and electronics and electricity are not a good mix.
The impurities in 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 start immediately and is ongoing until it has been properly cleaned away.
Hopefully after you have done all this the laptop might possibly work correctly again.
Here’s the owner’s manual which will help you to disassemble the laptop. It details the necessary pre-requisite steps and then the procedures for removing/replacing all the major components of the laptop.
If after all this it still has problems, search online for (insert motherboard’s ‘board number’) schematics (the board number is printed on the motherboard), to hopefully find the schematics for the motherboard. Smoke emanating from electronics pcb is never good so no doubt something is damaged and most probably will have to be replaced. If you do find the schematics then hopefully you know how to read them and also how to use a DMM (digital multimeter) as this is the only way that the motherboard might be fixed.
The alternative is to source a replacement motherboard and install that. The owner manual will be useful for that also.