At its home airport, a Boeing E75 was purposely landed in the grass adjacent to the runway. The airplane touched down hard, the left main landing gear strut separated from the airplane, the right main landing gear strut bent, the propeller struck the ground, and the lower left wing spar broke. Their were no injuries to the owner/pilot who was flying the airplane from the rear cockpit, or his friend, who according to the owner, was acting as pilot-in-command since his flight review was "expired."