Introducing a New Kitten to the Resident Cat

I have a 9 month old kitten which looks like a full grown cat! Now I have a 6 week old kitten. I have only had the new one for 2 days. There is no hissing or growling, but the older kitten tries to bite and attack the little kitten. The vet says to keep them apart for a few more weeks. The 9 month old has been neutered. Any suggestions?

By Vickie