Help. Weaning bottle for sleep

Raquel

My 18m old relies heavily on his bottle for nap time and bedtime. I’ve tried giving him his sippy cup and he wants nothing to do with it, though I don’t really want to wean him from bottle only to have to wean from sippy cup. I’m going to wean down the # of oz in the bottle now as well.. but so far that hasn’t helped much either. Can anybody provide tips on how to do this or what was the most effective method for you? Thank you!!