Take it apart and clean the computer and work from there

To do this, you need a pentelobe screwdriver for the screws on the case of the laptop and T5 torx

Clean everything in isapropal alcohol and soak all the parts in it for 24 hours, let it all dry and reassess the situation with a new battery installed, the old one may have shorted

Here are the guides, don't soak the fan, display assembly or keyboard/palmrest assembly, but the other parts have to be soaked to avoid further issues

http://www.ifixit.com/Device/MacBook_Air...

http://www.ifixit.com/Wiki/Electronics_W...

MacBook Pro and Air 5-Point Pentalobe Screwdriver

T5 Torx Screwdriver

Take it apart and look for the LSI (liquid submersion indicators. They are white dots and turn red when exposed to liquid. If you're lucky, it didn't get to the logic board and all you will need to do is replace the upper case.

open the bottom case to check the damage to logic board and battery. took out the logic board and clean it properly . then w8 for to dry the board or heat up to dry vastly. then try to power up . it still same then have to change the logic board then it may be expensive to change this . try it on the ebay and check with local repair shops. otherwise dismantle it and sell it on the ebay will get the more money on ebay thnx