Tapping into the Fuel Rail

My neighbor has a 1996 Mustang GT with the 4.6. He suspects that someone might have put some water into his gas tank. He wants to remove some fuel to test it from the fuel rail. He does not have a fuel injector tester. Is there an easy way to remove a quart or so of fuel from the fuel rail? What type of fitting is necessary to tap into this test port.

There should be a conection somewhere on the fuel line to test fuel. Im not sure where it would be on that car, but its like a mini-air hose fitting. Tell him to run a bottle or 2 of alcohol depending on how big his tank is and it will get rid of any water that may be in is fuel. Good luck.