I agree that there is no way to night-wean without tears. Toddlers love to nurse, and they often cry when we tell them they can't. And if the child depends on nursing to fall asleep, then she will certainly also cry because she is tired and frustrated and doesn't know how to fall asleep.
How many tears will depend on the toddler, and maybe on how gradually you approach night weaning. One way to make it easier is to help your child learn to fall asleep without nursing, before launching into night weaning. To do this, adopt a bedtime routine that does not include nursing to fall asleep. (I would advise singing, rubbing her back etc, but not rocking or anything that takes you out of the bed.) Your daughter may protest at first, but she will gradually learn to fall asleep without nursing. That in itself is a valuable skill. Another big benefit is that when your daughter gets to that light part of the sleep cycle, she will be less likely to wake up, because when she awakens slightly, she will be able to put herself back to sleep. So while she may still wake up to nurse (hard to resist!), when she is tired enough, she will just roll over and go back to sleep.
After a few months of falling asleep without nursing, you may well find your daughter rarely waking up at night. But if she is still waking to nurse, you can decide at that point whether you want to night wean completely.
If you decide to night wean, you would start by explaining it to your daughter. I would also recommend that you act it out with her Teddy bears, so that she understands what you are talking about. Then, before bedtime, remind her that no more nursing while it's dark. You can tell her that your breasts are sleeping, or put bandaids over them, or whatever. But make it clear that this is the last nursing until it is light out. Then when she awakens, you explain again that the breasts are sleeping. She will, of course, protest in sadness and anger. Empathize. But don't nurse her. Hold her while she cries. Since you will have taught her to go to sleep without nursing, she will be able to fall asleep again if she chooses to. Of course, use any strategies you usually use at bedtime to help her sleep, like singing or rubbing her back.
Indeed, she will cry, but you are not leaving her alone to cry. Saying No does not destroy her trust in you. You will have to say No to many things over the years. She may think your decisions are arbitrary, but if you empathize, and stay kind and respectful, she will learn that her feelings and happiness do matter to you, even when you have to say No.
This is obviously a very personal decision. My own opinion is that it is fine to night wean at age two. Your daughter will probably nurse more during the day for awhile, just to reassure herself that you are still there for her in that way. But as kids grow, it is natural for us to find other ways to stay connected with them, beyond nursing. I don't think this affects her negatively in terms of security, trust, etc. And if it makes you a better mom to your two year old because you are less tired, then I would call it positive for your daughter, on balance.