Hi! I have two boys I bf'd for over a year, I think I can actually help with this one! :)
First, the reason for waiting until your child is over a year old is all about allergies, kids are more prone to having an allergic reaction earlier. If you have no history of allergies it should be okay, he is awfully close to his first birthday.
I personally give my kids soy milk. We have no allergies, but soy is good for them, it comes in a kid fortified formula (that's quite sugary, so you might want to use it or not), it tastes delicious, and it has less chance of an allergic reaction.
The second part is the harder part. How often does your child nurse throughout the day? If he still nurses frequently, I would keep the morning and night nursing the same, as it won't be changing, and then cut the number of feedings in half. If he's on a relative schedule, like you know around what times he usually eats, it will be easy. Just skip to every other one. Also, since you're trying to wean through those times, offer to nurse him after he's had the milk, rather than before as many bf'ers will recommend.
Is he eating solids? A lot? I would also offer to nurse after he eats.
As long as he's getting to comfort nurse some throughout the day and you're getting the edge taken off throughout the day, you should be okay. If you feel yourself getting engorged, you really should pump, or nurse. Don't get yourself too engorged or it can lead to much more discomfort.
My sons both just naturally nursed a lot less once they started drinking from something other than me, and it was around 11 or 12 months that they did. My supply dropped quickly when the need for it wasn't there, and by the time they fully weaned, we were both ready. I guess really, there may be a few hard days when he asks to nurse and you give him something else, but I wouldn't expect those hard days to be too many. While they miss it terribly, they have relatively short memory spans, and they understand much more than for what we give them credit!!
Good luck!
If you have any more questions, email me! I might be helpful with those, too! :)
B.