if you have a large house, restrict him to a room where he has his litter box food and water for the first couple of days.
show him where the box is usually they know what to do because mom has already taught them.
They just need a smaller safe area where they have easy access to their stuff.
When you bring them home, have the litter box set up already. Simply put them in the litter box, and they will scratch a little, then get out. From that point onward, they are trained...
Spread some kitty litter in a shallow container. I use a plastic tote lid. They are hard wired to bury their crap so set them in the litter and and they will figure it out