Agreed, any fixings you try will probably invalidate the warranty on that part, or any faults caused by it.
Main KIA dealer is your friend
Good Luck, let us know how you get on ok.
From what I understand the manual (and it was a while when I took a look there), the lamp actually says water in the fuel filter.. at least that's my understanding.
Anyway, as already suggested, take it to KIA and they should sort it out.