Buy kitten tray with low sides, without it you can not do. Buy toilet for adult cats, in which baby will be uncomfortable to climb, it's pointless - he probably will not appreciate the "gift". In a tray place the filler, torn newspaper or sand (a lot of dirt).
When the litter box will be a start teach the baby to go in it. When the kitten begins to dash around the apartment and look for a hiding place, immediately carry it into the tray, because he probably wants to use the toilet. Carefully observe fluffy after he eats, after a delicious lunch, the kittens and make puddles on the carpet or on upholstered furniture.
If the baby has already managed to go to the toilet in the wrong place, slightly to poke his nose, but only next to the puddle. And then take it in the tray and strictly explain that to go to the toilet only here. Animals well enough to understand speech and intonation of the human voice. Never hurt the kitten because he does not have time to get to the right places, so he'll never learn to walk in the tray. Explain all is calm, stern voice, this will be enough.
Thoroughly rinse the "favorite" places that kitty often goes to the toilet. Animals are attracted to their own smell, it confuses the kids from the right path. Can soak a small rag in the urine and put it in the tray, then next time the kid will smell the inviting aroma and will go where it smells.
Some kittens know what is required of them the owner just a few days, while others can't get used to go to the toilet in the tray. In any case, be patient and continue to explain to the kid where and what to do. Makes no sense to cry and worry, the time will come, and the kitten will begin to do what you need. Be kind and considerate towards animals because they are defenseless.