For starters make sure you back your car right up to it to where your fuel door and her's are close and siphon out as much gas as you can out of her tank and into yours.
This way when you drop the tank it is light.
If you have replaced your fuel pump on your mustang you should have no problems. The only thing different is the tank sits closer to the center of the car and the tank is wider and longer but it is about half as thick as a mustang gas tank.