From what I've heard, if he decides to wean himself, he'll do it as he learns to stop feeding to sleep. It won't be for some time yet though
For us, it stopped working (although she's been doing it again recently); so when she started fussing at the breast, I'd stand up, pull my top down and make sure it was a high-neck, hard-to-get-into top, and hold her up on my shoulder and walk/sing. I used the same song that I'd sing to her when she was feeding to sleep (I'd been trying to build multiple sleep associations) and she'd usually grizzle a bit, and sometimes shriek, but if I remained gentle and calm and kept walking/rocking/singing to her, she'd be asleep usually within 2 minutes. After a few weeks of that, she'd just accept that when I stood up and started walking, she'd lay her head on my shoulder and it still took a few minutes (sometimes up to 10) to nod off but there was no grizzling.
These days she goes down for her naps without a feed, and that just involves a cuddle and a song (or 5!).
I'm hoping eventually she'll get interested in stories, so I can sit/lie in bed with her and read to her and she'll just listen till she nods off. Might be a bit optimistic though, as we can't even get through one tiny story atm!