Soo. When it's time to wean the baby off the boob

Rachel

What does that process look like? Currently I work 3 days a week and only pump on those days at work. The rest of the days I just nurse him. He will be 10 months old at the end of the month. I'm thinking of introducing formula. He takes a bottle fine while I'm at work. When I start to wean him should I still pump? What do I do when my breasts fill up? Does it hurt?