I have done this same thing for my 2000 GT project car.
Step one. Drain the gas tank. It's quite possible to disconnect the fuel filter and power the fuel pump directly using a battery charger. There's a round connector near the rear of the gas tank. The wire colors are RD/BK and BN/PK. Be careful not to short out any other pins. If you hear the fuel pump run but nothing comes out then reverse the wires.
When I had to do this I disposed of the nasty gas by putting a gallon or so into all of my other cars and my neighbor's cars. I figured a small amount of sale gas mixed in with good gas won't hurt. Otherwise you would have to pay to have the gas disposed of.
Strongly consider sending the Fuel injectors out for cleaning and flow testing. I have had good results using InjectorRX.com. Once cleaned and tested they are as good as new. Much cheaper than new.
Change the oil.
Make sure the battery is fully charged. Battery terminals clean and tight.
When starting for the first time, pull the fuel pump fuse or disconnect the fuel pump connector so that it won't start. Crank the motor until oil is seen down the oil filler neck.
If you are super anal then pull all of the spark plugs and put a small amount of oil down the spark plugs holes. Crank the motor with the spark plugs out.
Re-enable the fuel pump. Turn the key on/pause/off several times WITHOUT cranking. Listen for the fuel pump to run each time. This is needed to re-pressurize the fuel system.
Cross fingers.
Start car.
Have beer (or begin trouble shooting).
1996+ Crank with no start check list
http://www.allfordmustangs.com/forums/4-6l-tech/336452-1997-mustang-wont-ignite.html#2984838