What /pine said is true, the box blade requires some proficiency to use well, also top and tilt is most convenient. Changing the top link length dramatically changes the bite of the blade by changing its angle relative to the ground. So you might start out, in an area you want to remove soil from, with the top link shorter so the blade digs in. Then, as you reach the area you want to spread that dirt, you lengthen the top link and the box blade first comes level with the ground and then a positive angle that feeds dirt under the blade and smooths it out in place.
That's the way it's supposed to work! But, if you don't have a hydraulic top link, it's not practical to make all those adjustments on the fly, so you will likely set the top link for digging and then lift the box slightly so the blade just moves along the surface to drag the dirt to where you want it. This works, but it one whole lot more difficult to do well than with that top and tilt. You will end up with some bumps and mounds in your work area - - if you are trying to drive over that uneven ground, the front wheels go up and the box digs in more - frustrating!
But, if you are backing up and using the blade to push, the tractor gets to roll on that smooth surface and the box stays sort of level - great! Except when pushing, the box scraper can bend your 3-point hitch and parts as they were engineered for pulling, not pushing.
There are some good instructions on line about using the box scraper, you'd be ahead of the game by reading up on it before renting one. Good luck and have fun.
