How-to-train-a-cat-to-use-the-toilet-outside, to get a litter-trained cat to go to the bathroom outside, start by choosing an out-of-the-way spot, like a corner of the yard or under a bush or tree. then, spread some of your cat’s preferred litter over the spot, along with some fresh waste from its indoor litter box.. Where is his litterbox? try moving it closer each day to his exit point and then put it outside for his use. when you notice that he no longer uses it then he is already doing his toilet in the yard., instructions. step 1: move the litter box move the litter box close to the door the cat will use to go outside. show the cat the new location of their litter box. keep the box there for a few weeks until they are familiar with the location.