Digging up and disposing is the best way. If you aren't concerned about other plants in the area or growing something in its place right away, you can spray with Hi-Yield 2, 4-D but it is a potent herbicide.
The gardener's friend, vinegar in a spray bottle, should work. Here's an article that explains more about this grass and the best time to remove it. Wishing you the best.
Hi Brenda: Here are a couple of sites that may help: