In a controlled manner, set your shoulder blades on the bench. Set one leg at 90 degrees to the ground and drive up with that glute. Set the other leg at its respective 90 degrees
Press upward and set the dumbbells at the top
Perform controlled presses with both dumbbells for the allocated rep range, then change to the other side
Each rep, ensure you're driving upward with the hip of the leg in contact with the ground (activating your glutes and core)