Hi, There's no easy way to rid your yard of ground hogs. You could try live trapping, but they are pretty hard to catch There are also spray repellents you could try around their holes which are available at garden centers and home stores.
Shoot them, the lead acts as a great deterrent. They are super destructive, I've seen barns toppled after they've tunneled under the floor. Live trap? Take it about 20 miles from their "house", or they'll reclaim it.