Stop Nursing

I’m ready to stop nursing my son. I just can’t ha sleep it anymore. My boobs are always so big and uncomfortable, and I can barely keep up with the demand my son needs. What’s the best way to go about it? Wean? Or cold turkey? And how long does it take for your boobs to shrink back down, I want to be able to go for runs again and do my workouts and not worry about being uncomfortable from my chest