how to introduce a kitten to an older cat?

Start by having someone else bring the kitten into your home. Then put the kitten in a seperate room, and be sure to spend extra time with your tabby boy. Let them sniff each other under the door for a few days. Then switch them for a few hours so he can smell the kitten's area and the kitten can be in his area. Do the switch a few times, the next day and then see if opening the door will lead to a friendly meeting. There will probably be some posing and hissing anyway, just reassure your tabby that he is still loved and he will accept the kitten.

From personal experience, adult cats are not aggressively hostile to kittens. I just had a stray kitten who upped and moved in with us a few weeks back, and she had no trouble adjusting with my 3 adults, two of them tabbies. I did keep a close eye on them for a day or two just to make sure everything would be ok. My new kitty is doing well. We call her Tres, short for Trespasser.

I kept Maxie, a one-year-old cat, in the basement and only allowed him in the kitchen to eat. He also had separate dishes and his own litterbox. Of course, every now and then, my Columbus cat, who is 11 years old, would approach the newcomer and try to chase him. This went on for about a month and a half. Now Maxie has full run of the house. He and Columbus aren't friends, but they tolerate each other. Every so often, their paths will cross too closely and Columbus will go after him. But that rarely happens now. So, keep the cats apart for a few weeks. You can also get them used to each other's scents by putting your hand in an old clean sock and petting one cat with it, then the other. Make sure they have their own dishes and eat apart from each other. It'll all take time and patience, but the effort is worthwhile. Good luck!