3 Answers

If it's in your engine already, get an oil change. 

heat it  above boiling temp of water  until  moisture is gone

You don`t if it is in the crankcase.

You do NOT attempt to start the motor, to do so will cause $$$$ damage. Including a bent crankshaft. Big bucks.

Drain the sump and allow to drain for at least a couple of hours, preferrably overnight.

Fill the sump with el- cheapo NEW oil and run motor for 5 minutes.

Stop engine and drain this lot of oil also and allow to drain as long as possible.

Refill with quality oil.

Watch for any sign of milkyness on the oil dipstick, this indicates the presence of water.Back to draining.

This definitely works, I know because I had the misfortune to drive my car into a flooded creek that was a lot deeper than I thought.

I had driven through the day before but there had been rain up stream overnight

 This occured near Goondiwindi in western Queensland on the NSW. border and I had the car for years afterwards.