You can first switch out feeds with bottled breastmilk or formula, do those at times he isn't going down for a nap so he doesn't want the breast for warmth and comfort.
I found it best to eliminate night feeding first.
Do get ready to wean at night, if you haven't already, start establishing a structured bedtime routine with lots of elements that don't involve BF. Calm the house down, close all the curtains, turn noise right down (except for white noise) and dim the lights to help his brain and bodyclock get lots of sleep signals.
Give him a bath, put on PJs, read a book. You may want to try and give him bottled breastmilk or formula when reading books. You want him to get that full feeling BEFORE lying down to sleep so yiu can start disconnecting milk from sleep.
Don't play with him or make him hyper, turn the TV off so everywhere seems boring and ready for bed.
My kids were older but I would have a litany while carrying them to bed, "The sun is going to sleep, the birds are going to sleep, the animals are going to sleep etc. eventually I would get to the point where (whatver you call BF) is going to sleep".
You obviously can't do thar immediately, you need to build up to that. But you want to helo him feel sleepy.
I BF 3 kids and I found each time when I was ready to wean that's what made the difference. You have to be determined and not allow then to BF at night. I always expected fights and struggles for days, but it didn't happen. I think they know when you really mean business. But you have to be ready. Build up to it, don't introduce too many changes at once.