How to wean from the bottle?

Help! My daughter is 20 months old and we fight to get rid of the bottle . I’ve bought every sippy cup possible and she will take them but she won’t drink her milk unless it’s in a bottle especially at bed time she won’t even sleep with a sippy cup of water she has to have a bottle to sleep still . tried just hiding them and she will not drink anything unless she has her bottle . I’m scared she will dehydrate . Advice please !! Bottles have to go I know , she was partially breastfed but I stopped producing after 3 months . Any help or advice please !!! I’m worried about her teeth and health issues !