Weaning off of toddler formula

After a long discussion with the Pediatrician, we've decided it's time to pull him off of Pediasure and try to wean him off. His eating habits are getting better and I'm able to mix what he needs into his pastas. He's also getting a multivitamin. Anyways, I'm curious as to how we begin the weaning process. We can take it slow since I've got enough to get us through November and December. He drinks one first thing waking up and one right as he's about to go to sleep. He will drink strawberry whole milk if it's given to him, but often he ASKS for Pediasure instead. So I know he enjoys it, but it's time to move past it. Ideas...help!? He's almost 3yrs (in February) and I'd like him to be totally off of it by time his 3rd birthday hits at the latest.