If you have a company remove the foxes, they will probably euthanize them, and I think that would be a shame. I would either leave the area alone, or go ahead and toss your yard waste on the top, preferably when the foxes are out hunting (dawn & dusk mostly). I would make some noise approaching, to alert the foxes and give them time to vacate their den before you actually get there. I don't think the foxes will stay there forever.