[brcidd]

If it were mine, I'd pump it out by energizing the fuel pump and attaching a hose to the pressure test port, and pump the gas into clear container, like a one gallon pickle jar. I'd check each gallon for water in the bottom and decide to keep or dispose of each gallon by visual inspection. If I no longer saw any signs of water, I'd try starting truck, if still no start, then continue pumping.

Once tank is empty, I'd fill with a couple gallons fresh fuel and try to restart.