Gradually reduce it is my best advice. Start to sub one feed a day then a day or 2 later swap another feed to a bottle and keep going until baby is having bottle feeds only. Fingers crossed for you. Does you baby take a bottle usually? My youngest would drink breast milk from a bottle some times but when I wanted to stop breastfeeding he completely refused all bottles. Formula and breast milk. So finding a formula baby will drink it’s the hardest part. Good luck