Weaning from the Bottle

Nathanial is 10.5 months old. This means, according to both of my baby books, we have at least 1.5 months and at most 5 months to wean him from the bottle onto a sippy cup/cup. We've introduced him to the idea of the sippy cup. He drinks water and/or juice out of it during meal times, and we've been able to occasionally get a feeding in through the sippy cup.

Still, there are a few problems that are facing.

1. The limited movement in his right arm makes it harder for him to lift the cup up high enough for the liquid to flow.
2. He likes his bottle...especially during this teething phase. He sort of relies on it to go to sleep. Not a good thing, I know, but it is what it is.
3. Mamaw is not so supportive. Nana has successfully given two sippies of formula to Boo. Kudos to Nana. Mamaw really enjoys rocking and bottling. And I don't blame her. But I want to progress on this.

It's not like I'm going to take the bottle away from him tomorrow, cold-turkey without the weaning process. On the contrary, I do want this to be a gradual process. But, we've got to keep the ball rolling. I don't want a 3-year-old bottle sucker...

Any thoughts on this?