Also make extra fuss of the dogs so they don't feel put out.
We introduced a kitten to 2 old and grouchy cat haters (13 year old springer and 13.5 year old lab) and we kept the kitten in a puppy crate when we weren't around to protect him (Indy is now nearly 11 months old) And the dogs still had free roaming, they settled with him inside a week

though we didn't let Indy loose at night/whilst we were out until we were 200% sure that a) he respected the dogs and b) he knew his escape route if he needed it... which was at about 3 weeks after we got him
Now they are so close, Indy (and Misha when we got him a few months later) have given the dogs a new lease of life!