First thing you should've done was to put the kitten in a room by himself for a while, to help him get acclamated. Wipe him down with an old towel and let the older cats get a wiff. Do the same with the kitten. After a while, put baby gates up in the doorway, one on top of the other. How long have you had him? The kitten is still in his "kitten" stage. Once he gets neutered, he'll surely calm down. It'll take time between the kitten and the older cat to get used to each other. Just be patient.