G.B.
I am going to say we let the kids have their bottles until they were done with time on their own. J was not ready until he was not ready until after he was 2. We told the Pediatric Dentist and he was okay with that as long as he didn't sleep with it in his mouth. He brought it to us one day and said he was done and wanted a cup. He never looked back. It can be a fight but why? Why fight and fight over something that is really no big deal? Having a bottle until they are ready is what older moms tend to do because they know that it's not a big deal and that it will eventually work itself out.
With my older daughter I took the bottle away after an injury to her top teeth. She started sucking her fingers and ruined her mouth and hands.
If your child needs to suck they will find something to suck.
As for the milk you have to transition them from formula to the milk gradually.
Start adding 2 oz. of whole vitamin D milk to the bottle then adding 6 oz. formula. Do this for about a week at most then go half and half. Then after at least a few days of her doing really well and taking it all the time then go to 6 oz. milk to 2 oz. formula. If she does really well with this let her stay on it for a few days then go to while milk all the time. Her little tummy cannot take the cold turkey of stopping formula and going whole milk all the way.It is not very fun for the person changing the diapers.
As for forcing your child to go from one thing to another and "Making" them do it just seems like your asking for a hard fight.