I just went through this a couple of months ago with my youngest. I was ready to have my body back(that and all my nursing bras were worn down to nothing but strings and rags and I didn't want to have to buy new ones!!).
I started by taking away all the nursing that I knew were just for pleasure. Leaving the more comforting ones alone (for us it was at story time, after nap, and first thing after breakfast). Then I took away the after breakfast one knowing she had just ate more then her share of solid food!! After that was the story time feeding, and then the after nap.
You just have to prioritize the specific nursing times and slowly start taking them away! Replace the time spent with playing instead. One of my daughters favorites was playing with blocks, so every time she asked to nurse I got down and played with her. I usually offered her a cup of milk too... For my daughter it helped that I warmed up the milk and held her really close. As a side note(but use at your own discretion): When she finally accepted the warmed milk it was way warmer then what I would have assumed was safe for her!!
Another helpful thing is that I realized my daughter would ask more often if I was sitting, she knew I was still and my lap was free. If I got up and started doing something (cleaning or whatnot) when she asked she was fine and more distracted by whatever it was I was doing!!
And like someone said... If you say no to a nursing, mean in, don't cave in!