I nursed my son until he was 15 months, and weaned because I was pregnant (20 weeks). I can only say - I am so glad I did. He is now 18 months and sleeps all night. In fact, as soon as we had weaned completely (which was hard - but worth it) he started sleeping 8 - 10 hours in a row. He had NEVER slept that long before we weaned.
I started by eliminating the day time nursings. Skipping the first thing in the morning nursing was easy because we just got up and had breakfast right away. After about 2 weeks we then we started skipping his morning nap, which was right around 14 months, which was a great way to skip a second nursing, and he was then so tired after lunch that we started skipping that third before nap nursing almost right away. Bed time was harder, but because we had a routine for his afternoon nap, we followed the same for bed time and within a week he was down to the 1 night time wake up. I let him have that one for about a week and a half, then eliminated it. That was the hardest one to get rid of, because he would then wake up every 1/2 hour until morning after he didn't get his nursing, but it only lasted about 3 or 4 days, then magically he was sleeping all night. Which was HEAVEN.
I never let him cry it out, or made him "suffer" I still got up with him, and just told him that there was no more nursing, and would either rock him or sit by his crib until he fell back asleep.
Good luck - and let us know how it turns out!
J.