What to do about night feedings and my 9 month old?

My son is 9 months old and he still wants night feedings. He wakes up a few times a night to suck on his bottle. I know he's not actually hungry because he only takes a few sips each time and falls back to sleep. He's using his bottle as a comfort item, and is not able to self soothe. How should I go about weaning him from his night feedings?