Weaning my 2 1/2 year old off the bottle

Hey moms so I’m finally trying to get my toddler off the bottle, he only drinks milk in it, he’ll want it for nap time and at night he’ll even wake me up in the middle of night for it but it gets exhausting especially cuz I’m 31 weeks pregnant. I know he likes it more for comfort but he’s getting too big and it’s becoming a bad habit, I’ve tried giving him milk in a sippy cup but he refuses. Today is my first day giving him a nap with out his bottle an it was a success! He cried for 10 mins but now he’s asleep! Any tips on how to completely getting him off the bottle?