How do I get my 2-year-old to give up the bottle?
In my opinion, the important first step to getting a 2-year-old to give up the bottle is to be convinced that your 2-year-old needs to give up the bottle. Given that prolonged bottle use can put children at greater risk of tooth decay, limit their interest in foods, and interfere with healthy sleep and feeding routines (to name but a few), this is a great time to switch your 2-year-old to a cup.
By the fact that you asked the question, I assume that you are already convinced that this is a very good idea and are prepared to help your toddler do so. For you, like many parents of bottle-toting 1- and 2-year-olds, the question then becomes one of extraction. In other words, how do you go about taking the beloved bottle away. The first point I always make to parents is that the task certainly doesn't become easier the older your child gets because as babies turn into toddlers, their attachment to the bottle typically becomes less about nutritional necessity and more about habit and comfort. Even by 1 year of age, the recommended amount of milk children need to drink each day drops considerably at a year, when they are switched from breast milk or formula to regular cow's milk. At the same time, 1-year-olds are usually becoming much better at eating table foods and three meals a day, and have the skills needed to pick up, hold, and drink out of a cup.
At the age of 2, it's therefore safe to say that most kids are fully capable of drinking out of a cup (or would be if they were no longer given a bottle). Bottle drinking may admittedly seem easier and less messy, but the fact that it's so easy to drink from a bottle actually poses a problem in that toddlers who are still drinking out of bottles often drink more milk (and consequently eat less solid food) than is good for them.
So what does that mean for you? If you haven't already, make sure your toddler's bedtime routine does not involve a bedtime bottle. If it does, adjusting your child's bedtime routine so that you make bath time, tooth brushing, and books (not bottles) your child's cues that it's time to go to bed can really help. Once you've committed to the need to get rid of the bottle, also make sure to adjust your expectations so that you don't expect your toddler to drink 24 to 32 ounces when 16 to 20 is more typical, and make sure you have toddler-friendly cups on hand. Offering milk (in a cup) with meals and water with snacks will help set your toddler up for healthier lifelong drinking habits.