I think the most important "readiness" is the parents
DD was fairly attached to her dummy and when she was almost 3, and we were ready for a couple of nights of broken sleep (many wise people told me the whole process takes 3 nights) we prepared DD, rounded up all the dummies (6 in total) and went to the shops. I worded up the checkout guy that DD would be paying for her toy in dummies and we went to the toy section. I suggested she buy a baby and she was pretty open to that suggestion, because then she would have something to go to bed with.
She paid for her baby with 6 dummies which the checkout guy then binned (if you give in after something like this it will be 10 times harder) and we left the shops dummiless.
Bedtime rolled around and she really wanted to cry when she realised that there were no dummies but she didn't, and I believe its because it was her choice. We didn't force it, she chose to buy baby.
Poor babies hands got chewed and she woke up a couple of times for 3 nights... my wise friends were right.
She never once asked for the dummy but we talked about how she was a big girl and talked a lot about baby.

You need to be ready and committed. Its really not kind to give in once you've made the call, I don't think, its confusing.
We used lots of other comfort measures to get through, back tickles, milk, sleeping next to her. 3 days of comforting and lots of love and no more dummies!
She sleeps so much better without them now.
Good luck!