Free standing tubs – Independent baths are also known as immersion baths or foot baths when imitating the old models. They are easier to install than wall bathtubs, and, as the name states, are designed to do away with the small problems of life.
Put something like a heavy wooden box or a strong toolbox that supports the weight of the free standing tubs. Cover the box with something that does not scratch the surface of the tub. If you have any packing material that came with the bath, you can use it. Place the tub on top of the box, raising it well enough to be able to work under it. And pay attention to the position of each foot. They cannot be changed because the tub is level factory.
For install both feet on the side of the tub that has the drain. People will be needed to install each foot, one to hold the bolt and one to center the foot on the clamping screw without scratching the tub or force threads. Install feet on the opposite end. Remove the structure that was supporting the tub, leaving it on the feet. If the free standing tubs swing, adjust the feet by tightening or loosening the washers. Once the bath was leveled at the factory, the oscillations are probably due to variations of the bathroom floor.