Impact should do it. You can also stick a breaker on it, put the end of the breaker on the ground and bump the starter. That's assuming the 4V rotates clockwise if you are looking at it from the front.
2000 Mustang GT Steeda #0048 34k miles. 99 Cobra 4V swapped, FTBR IRS swapped, exhaust, tuned by James Gordon.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.