Start sitting on the ground facing the landmine attachment, holding the end of the bar in both hands slightly in front of and above your chest while holding your feet off the ground and knees bent.
Bending your elbows as little as possible and keeping your core tight and feet elevated, lower the end of the bar with control to the ground on one side of your body, then contract your obliques to return the bar to the center. Repeat on the other side.
Repeat for the desired number of reps.