My LO is 11.5 months and we were previously on 3 x 8oz bottles per day, but recently he started refusing his afternoon bottle. So we do 2 x 8oz bottles at wake up and bedtime, and then whole milk in a sippy at lunch. Whatever he doesn't take at lunch I dump and offer a new cup after his PM nap. He is starting to slack on his wake up bottle, but I'm going to try to hang onto it for a little while longer.
In any case, I think it is best to wean 1 bottle at a time and start with the daytime bottles first, then the morning one, then eventually the bedtime one (though I find lots of people don't wean that one for quite a while).