You can leave them there, but I recommend you protect them with some covering of chicken wire or some type of strong mesh wire where the adult boxies can not get through it. I just saw one of my boxies that dug a hiding place for herself to lie in the soil exactly the same spot where I took out a clutch of eggs 2 weeks ago. I would have lost that clutch if I didn't take it out. (since I didn't protect that spot with chicken wire.)
If you decide to take out the eggs, you can just get a plastic shoe box or plastic food container, fill it with soil (I use vermicullite), moisten it to where you can squeeze it into a clump without it dripping wet & place the eggs in it. You HAVE TO PLACE THE EGGS EXACTLY THE WAY THEY WERE FOUND!. I normally make a mark with a pencil on the egg so I know which way is up and then I move it carefully. If the egg is turned over after the egg has begun to incubate, chances are, the hatchling will die.Punch some holes through the top for circulation and place them in a warm, dark place. Time of incubation varies depending on the temp. You don't have to buy an incubator. I make my own - I use styrofoam boxes. I don't use the "cooler" types - I use the heavier type for keeping frozen foods and use glass for a top and leave a little gap for air. I like to watch without having to lift off the top. Good luck!