Water In Oil

I have a freind with a 04 honda rancher 400. we where riding the other day and his machine stalled in a deep water hole. We found water in the oil.
He found out the factory snorkle had came loose at the bottom
he has changed the oil and filter and now it starts.
What does he need to do now.
it did not run long after the water got in isd the engine hurt.

 

if the water was real muddy, i would change the oil and filter twice (for the first time just use the cheap stuff) to fluch out all of the crap that might have goten in. when you cange the oil the first time, let it run for 1/2 hour to make sure the oilfilter catches all the gunk