1yr weening help

How do you slowly wean when baby is over a year? Right now she only nurses 2x during the week (takes 3 bottles at daycare), and on weekends nurses 4-5x. I'm just not sure how to go about it. I'm sure she's not going to be happy, esp dropping the before bedtime session. I assume you slowly mix milk with breast milk... do you replace one bottle for each nursing session, once a week? Then the next week replace two nursing sessions with bottles? How much milk vs breast milk do you do? I'm so lost & nervous about it!