Doug,
I elected to buy a GT500 fuel filter and 6' of fuel hose and 2 clamps.
To relieve the fuel pressure in the lines: Disconnect the FPDM module in the trunk and start the car and let it stall out and die. I then crank it 10 seconds to relieve the fuel pressure and then disconnect my battery.
The GT500 fuel filter has the exact same male connector as the fuel rail so when you disconnect your fuel rail on the driver side you simply plug the filter into the fuel rail feed and then the hose into your fuel jug. I then reconnect the battery and the FPDM module. I then load a tune for my ecu to turn my fuel pump on with the key on and it'll drain the tank through the filter and into my jug. If you want you can relieve the pressure of the rail again at this point and then disconnect the filter and reconnect the fuel rail.
I then swap tunes back and fill up with my other fuel choice and you're good to go.