I've had to rewrite this so many times that I decided it was time to just copy/paste it here (edit: I've rewritten it a bit for this blog). My decision to night wean Lilly was brought on by pregnancy--I experienced severe aversion at night and finally had to try, but was unwilling to continue if my little girl experienced any distress from it. She was around 20 months:
What I did was start telling her (she called nursing and my breasts "nummas" at the time) "The nummas are sleeping". We started incorporating saying good-night to the nummas into the good-nights of our bedtime ritual and that's when she'd stop for the night (then we'd cuddle to sleep from there). The first two nights, she woke up and wanted to nurse--the first time, she wasn't okay with the nummas sleeping, so I "woke one up" and she nursed back to sleep. That was the only time she cried about it (she whined a couple times, but I distracted and cuddled her--she began demanding cuddles instead) and not to the point of tears. The next night, she woke a couple times, but accepted that they were asleep. The next night, she didn't wake up at all.
I was only planning to test the waters, to see if it was okay with her, because I didn't want to force her into anything she wasn't ready for, but she was clearly ready. That's how we gently night weaned. And I had every intention of stopping the attempt if it distressed her.
Dad was not involved because she needed the comfort to come from me. But he could put her to bed only a couple months later if he needed to (although he goes to bed before everyone else, so that's not really a thing anymore). By the time this post was written, she even put herself to bed.
She regressed and needed to night nurse again, so we started again (since I was already up nursing her sister, it didn't bother me at all) but it worked while I needed it to and if her sister wasn't waking her up at night, I knew she'd still have be night weaned. Within a few months of this post originally being written, she night weaned again, this time on her own.
Naomi night weaned on her own around her second birthday. I thought I'd try to night wean her like her sister--it never happened. It was like she sensed it every time I thought about it and went on nursing frenzies, so I stopped thinking about it and slowly, she stopped on her own.